1
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Kammeraad JA, Das S, Argüelles AJ, Sayyed FB, Zimmerman PM. Conformational Sampling over Transition-Metal-Catalyzed Reaction Pathways: Toward Revealing Atroposelectivity. Org Lett 2024; 26:2867-2871. [PMID: 38241482 DOI: 10.1021/acs.orglett.3c04047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2024]
Abstract
The Py-Conformational-Sampling (PyCoSa) technique is introduced as a systematic computational means to sample the configurational space of transition-metal-catalyzed stereoselective reactions. When applied to atroposelective Suzuki-Miyaura coupling to create axially chiral biaryl products, the results show a range of mechanistic possibilities that include multiple low-energy channels through which C-C bonds can be formed.
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Affiliation(s)
- Joshua A Kammeraad
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Soumik Das
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Alonso J Argüelles
- Synthetic Molecule Design and Development, Eli Lilly, Eli Lilly, Indianapolis, Indiana 46221, United States
| | - Fareed Bhasha Sayyed
- Synthetic Molecule Design and Development, Eli Lilly Services India Pvt Ltd, Devarabeesanahalli, Bengaluru, Karnataka 560103, India
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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2
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Rask AE, Li L, Zimmerman PM. Kohn-Sham Density in a Slater Orbital Basis Set. J Phys Chem A 2024. [PMID: 38602291 DOI: 10.1021/acs.jpca.3c08303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Finite, atom-centered Slater basis sets are used to determine approximate Kohn-Sham molecular orbitals. This is achieved by minimizing the kinetic energy plus the sum-squared difference between the Kohn-Sham density and the full configuration interaction density. As a result of the finite basis, a weight factor is introduced to balance the two minimization components. Results herein show that this can be done systematically, without sensitive dependence on the choice of scaling factor. In addition, the algorithm is applied to the LiH diatomic for fractional electron counts, where stretching the bond introduces significant reorganization of the electron density. The analysis will show the correct KS orbital structure and reveal the effects of correlation and electron locality on the KS solutions.
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Affiliation(s)
- Alan E Rask
- SandboxAQ, 780 High Street, Palo Alto, California 94301, United States
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Liying Li
- Department of Mathematics, University of Michigan, 530 Church Street, Ann Arbor, Michigan 48109, United States
- Department of Mathematics, Southern University of Science and Technology, No. 1088 Xueyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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3
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Wang Y, Torma KJ, Pyser JB, Zimmerman PM, Narayan ARH. Substrate-Selective Catalysis Enabled Synthesis of Azaphilone Natural Products. ACS Cent Sci 2024; 10:708-716. [PMID: 38559303 PMCID: PMC10979483 DOI: 10.1021/acscentsci.3c01405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 02/05/2024] [Accepted: 02/16/2024] [Indexed: 04/04/2024]
Abstract
Achieving substrate-selectivity is a central element of nature's approach to synthesis. By relying on the ability of a catalyst to discriminate between components in a mixture, control can be exerted over which molecules will move forward in a synthesis. This approach can be powerful when realized but can be challenging to duplicate in the laboratory. In this work, substrate-selective catalysis is leveraged to discriminate between two intermediates that exist in equilibrium, subsequently directing the final cyclization to arrive at either the linear or angular tricyclic core common to subsets of azaphilone natural products. By using a flavin-dependent monooxygenase (FDMO) in sequence with an acyl transferase (AT), the conversion of several orcinaldehyde substrates directly to the corresponding linear tricyclic azaphilones in a single reaction vessel was achieved. Further, mechanistic studies support that a substrate equilibrium together with enzyme substrate selectivity play an import role in the selectivity of the final cyclization step. Using this strategy, five azaphilone natural products were synthesized for the first time as well as a number of unnatural derivatives thereof.
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Affiliation(s)
- Ye Wang
- Life
Sciences Institute, Department of Chemistry, University of
Michigan, Ann Arbor, Michigan 48109, United States
| | - Katherine J. Torma
- Life
Sciences Institute, Department of Chemistry, University of
Michigan, Ann Arbor, Michigan 48109, United States
| | - Joshua B. Pyser
- Life
Sciences Institute, Department of Chemistry, University of
Michigan, Ann Arbor, Michigan 48109, United States
| | - Paul M. Zimmerman
- Life
Sciences Institute, Department of Chemistry, University of
Michigan, Ann Arbor, Michigan 48109, United States
| | - Alison R. H. Narayan
- Life
Sciences Institute, Department of Chemistry, University of
Michigan, Ann Arbor, Michigan 48109, United States
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4
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Zhelavskyi O, Parikh S, Jhang YJ, Staples RJ, Zimmerman PM, Nagorny P. Green Light Promoted Iridium(III)/Copper(I)-Catalyzed Addition of Alkynes to Aziridinoquinoxalines Through the Intermediacy of Azomethine Ylides. Angew Chem Int Ed Engl 2024; 63:e202318876. [PMID: 38267370 PMCID: PMC10939844 DOI: 10.1002/anie.202318876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 01/26/2024]
Abstract
This manuscript describes the development of alkyne addition to the aziridine moiety of aziridinoquinoxalines using dual Ir(III)/Cu(I) catalytic system under green light-emitting diode (LED) photolysis (λmax =525 nm). This mild method features high levels of chemo- and regioselectivity and was used to generate 30 highly functionalized substituted dihydroquinoxalines in 36-98 % yield. This transformation was also carried asymmetrically using phthalazinamine-based chiral ligand to provide 9 chiral addition products in 96 : 4 to 86 : 14 e.r. The experimental and quantum chemical explorations of this reaction suggest a mechanism that involves Ir(III)-catalyzed triplet energy transfer followed by a ring-opening reaction ultimately leading to the formation of azomethine ylide intermediates. These azomethine intermediates undergo sequential protonation/copper(I) acetylide addition to provide the products.
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Affiliation(s)
| | - Seren Parikh
- Chemistry Department, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yin-Jia Jhang
- Chemistry Department, University of Michigan, Ann Arbor, MI 48109, USA
| | - Richard J Staples
- Department of Chemistry and Chemical Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Paul M Zimmerman
- Chemistry Department, University of Michigan, Ann Arbor, MI 48109, USA
| | - Pavel Nagorny
- Chemistry Department, University of Michigan, Ann Arbor, MI 48109, USA
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5
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Skinner KC, Kammeraad JA, Wymore T, Narayan ARH, Zimmerman PM. Simulating Electron Transfer Reactions in Solution: Radical-Polar Crossover. J Phys Chem B 2023; 127:10097-10107. [PMID: 37976536 DOI: 10.1021/acs.jpcb.3c06120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Single-electron transfer (SET) promotes a wide variety of interesting chemical transformations, but modeling of SET requires a careful treatment of electronic and solvent effects to give meaningful insight. Therefore, a combined constrained density functional theory and molecular mechanics (CDFT/MM) tool is introduced specifically for SET-initiated reactions. Mechanisms for two radical-polar crossover reactions involving the organic electron donors tetrakis(dimethylamino)ethylene (TDAE) and tetrathiafulvalene (TTF) were studied with the new tool. An unexpected tertiary radical intermediate within the TDAE system was identified, relationships between kinetics and substitution in the TTF system were explained, and the impact of the solvent environments on the TDAE and TTF reactions were examined. The results highlight the need for including solvent dynamics when quantifying SET kinetics and thermodynamics, as a free energy difference of >20 kcal/mol was observed. Overall, the new method informs mechanistic analysis of SET-initiated reactions and therefore is envisioned to be useful for studying reactions in the condensed phase.
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Affiliation(s)
- Kevin C Skinner
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Josh A Kammeraad
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Troy Wymore
- Laufer Center, Stony Brook University, Stony Brook, New York 11794, United States
| | - Alison R H Narayan
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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6
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Abstract
The conventional approaches to the inverse density functional theory problem typically assume nondegeneracy of the Kohn-Sham (KS) eigenvalues, greatly hindering their use in open-shell systems. We present a generalization of the inverse density functional theory problem that can seamlessly admit degenerate KS eigenvalues. Additionally, we allow for fractional occupancy of the Kohn-Sham orbitals to also handle noninteracting ensemble-v-representable densities, as opposed to just noninteracting pure-v-representable densities. We present the exact exchange-correlation (XC) potentials for six open-shell systems─four atoms (Li, C, N, and O) and two molecules (CN and CH2)─using accurate ground-state densities from configuration interaction calculations. We compare these exact XC potentials with model XC potentials obtained using nonlocal (B3LYP, SCAN0) and local/semilocal (SCAN, PBE, PW92) XC functionals. Although the relative errors in the densities obtained from these DFT functionals are of O (10-3 to 10-2), the relative errors in the model XC potentials remain substantially large─O (10-1 to 100).
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Affiliation(s)
- Bikash Kanungo
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jeffrey Hatch
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Vikram Gavini
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
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7
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Prajapati B, Ambhore MD, Dang DK, Chmielewski PJ, Lis T, Gómez-García CJ, Zimmerman PM, Stępień M. Tetrafluorenofulvalene as a sterically frustrated open-shell alkene. Nat Chem 2023; 15:1541-1548. [PMID: 37783726 PMCID: PMC10624625 DOI: 10.1038/s41557-023-01341-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 09/04/2023] [Indexed: 10/04/2023]
Abstract
Electronic and steric effects are known to greatly influence the structure, characteristics and reactivity of organic compounds. A typical π bond is weakened by oxidation (corresponding to the removal of electrons from bonding orbitals), by reduction (through addition of electrons to antibonding orbitals) and by unpairing of the bonding electrons, such as in the triplet state. Here we describe tetrafluorenofulvalene (TFF), a twisted, open-shell alkene for which these general rules do not hold. Through the synthesis, experimental characterization and computational analysis of its charged species spanning seven redox states, the central alkene bond in TFF is shown to become substantially stronger in the tri- and tetraanion, generated by chemical reduction. Furthermore, although its triplet state contains a weaker alkene bond than the singlet, in the quintet state its bond order increases substantially, yielding a flatter structure. This behaviour originates from the doubly bifurcated topology of the underlying spin system and can be rationalized by the balancing effects of benzenoid aromaticity and spin pairing.
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Affiliation(s)
| | | | - Duy-Khoi Dang
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | | | - Tadeusz Lis
- Wydział Chemii, Uniwersytet Wrocławski, Wrocław, Poland
| | - Carlos J Gómez-García
- Departamento de Química Inorgánica and Instituto de Ciencia Molecular, Universidad de Valencia, Paterna, Spain
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA.
| | - Marcin Stępień
- Wydział Chemii, Uniwersytet Wrocławski, Wrocław, Poland.
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8
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Di Felice R, Mayes ML, Richard RM, Williams-Young DB, Chan GKL, de Jong WA, Govind N, Head-Gordon M, Hermes MR, Kowalski K, Li X, Lischka H, Mueller KT, Mutlu E, Niklasson AMN, Pederson MR, Peng B, Shepard R, Valeev EF, van Schilfgaarde M, Vlaisavljevich B, Windus TL, Xantheas SS, Zhang X, Zimmerman PM. A Perspective on Sustainable Computational Chemistry Software Development and Integration. J Chem Theory Comput 2023; 19:7056-7076. [PMID: 37769271 PMCID: PMC10601486 DOI: 10.1021/acs.jctc.3c00419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Indexed: 09/30/2023]
Abstract
The power of quantum chemistry to predict the ground and excited state properties of complex chemical systems has driven the development of computational quantum chemistry software, integrating advances in theory, applied mathematics, and computer science. The emergence of new computational paradigms associated with exascale technologies also poses significant challenges that require a flexible forward strategy to take full advantage of existing and forthcoming computational resources. In this context, the sustainability and interoperability of computational chemistry software development are among the most pressing issues. In this perspective, we discuss software infrastructure needs and investments with an eye to fully utilize exascale resources and provide unique computational tools for next-generation science problems and scientific discoveries.
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Affiliation(s)
- Rosa Di Felice
- Departments
of Physics and Astronomy and Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, United States
- CNR-NANO
Modena, Modena 41125, Italy
| | - Maricris L. Mayes
- Department
of Chemistry and Biochemistry, University
of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747, United States
| | | | | | - Garnet Kin-Lic Chan
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
| | - Wibe A. de Jong
- Lawrence
Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Niranjan Govind
- Physical
Sciences Division, Pacific Northwest National
Laboratory, Richland, Washington 99354, United States
| | - Martin Head-Gordon
- Pitzer Center
for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Matthew R. Hermes
- Department
of Chemistry, Chicago Center for Theoretical Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Karol Kowalski
- Physical
Sciences Division, Pacific Northwest National
Laboratory, Richland, Washington 99354, United States
| | - Xiaosong Li
- Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Hans Lischka
- Department
of Chemistry and Biochemistry, Texas Tech
University, Lubbock, Texas 79409, United States
| | - Karl T. Mueller
- Physical
and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Erdal Mutlu
- Advanced
Computing, Mathematics, and Data Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Anders M. N. Niklasson
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Mark R. Pederson
- Department
of Physics, The University of Texas at El
Paso, El Paso, Texas 79968, United States
| | - Bo Peng
- Physical
Sciences Division, Pacific Northwest National
Laboratory, Richland, Washington 99354, United States
| | - Ron Shepard
- Chemical
Sciences and Engineering Division, Argonne
National Laboratory, Lemont, Illinois 60439, United States
| | - Edward F. Valeev
- Department
of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | | | - Bess Vlaisavljevich
- Department
of Chemistry, University of South Dakota, Vermillion, South Dakota 57069, United States
| | - Theresa L. Windus
- Department
of Chemistry, Iowa State University and
Ames Laboratory, Ames, Iowa 50011, United States
| | - Sotiris S. Xantheas
- Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
- Advanced
Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Xing Zhang
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
| | - Paul M. Zimmerman
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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9
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Chen M, Ventura AM, Das S, Ibrahim AF, Zimmerman PM, Montgomery J. Oxidative Cross Dehydrogenative Coupling of N-Heterocycles with Aldehydes through C( sp3)-H Functionalization. J Am Chem Soc 2023; 145:20176-20181. [PMID: 37672664 PMCID: PMC10915535 DOI: 10.1021/jacs.3c06532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Existing methodologies for metal-catalyzed cross-couplings typically rely on preinstallation of reactive functional groups on both reaction partners. In contrast, C-H functionalization approaches offer promise in simplification of the requisite substrates; however, challenges from low reactivity and similar reactivity of various C-H bonds introduce considerable complexity. Herein, the oxidative cross dehydrogenative coupling of α-amino C(sp3)-H bonds and aldehydes to produce ketone derivatives is described using an unusual reaction medium that incorporates the simultaneous use of di-tert-butyl peroxide as an oxidant and zinc metal as a reductant. The method proceeds with a broad substrate scope, representing an attractive approach for accessing α-amino ketones through the formal acylation of C-H bonds α to nitrogen in N-heterocycles. A combination of experimental investigation and computational modeling provides evidence for a mechanistic pathway involving cross-selective nickel-mediated cross-coupling of α-amino radicals and acyl radicals.
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Affiliation(s)
- Mo Chen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Austin M Ventura
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Soumik Das
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Ammar F Ibrahim
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - John Montgomery
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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10
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Tribedi S, Dang DK, Kanungo B, Gavini V, Zimmerman PM. Exchange correlation potentials from full configuration interaction in a Slater orbital basis. J Chem Phys 2023; 159:054106. [PMID: 37530106 DOI: 10.1063/5.0157942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/11/2023] [Indexed: 08/03/2023] Open
Abstract
Ryabinkin-Kohut-Staroverov (RKS) theory builds a bridge between wave function theory and density functional theory by using quantities from the former to produce accurate exchange-correlation potentials needed by the latter. In this work, the RKS method is developed and tested alongside Slater atomic orbital basis functions for the first time. To evaluate this approach, full configuration interaction computations in the Slater orbital basis are employed to give quality input to RKS, allowing full correlation to be present along with correct nuclei cusps and asymptotic decay of the wavefunction. SlaterRKS is shown to be an efficient algorithm to arrive at exchange-correlation potentials without unphysical artifacts in moderately-sized basis sets. Furthermore, enforcement of the nuclear cusp conditions will be shown to be vital for the success of the Slater-basis RKS method. Examples of weakly and strongly correlated molecular systems will demonstrate the main features of SlaterRKS.
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Affiliation(s)
- Soumi Tribedi
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
- Michigan Institute for Data Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Duy-Khoi Dang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Bikash Kanungo
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Vikram Gavini
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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11
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Todtz SR, Schneider CW, Malakar T, Anderson C, Koska H, Zimmerman PM, Devery JJ. Controlling Catalyst Behavior in Lewis Acid-Catalyzed Carbonyl-Olefin Metathesis. J Am Chem Soc 2023; 145:13069-13080. [PMID: 37279356 PMCID: PMC10517625 DOI: 10.1021/jacs.3c01508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Lewis acid-catalyzed carbonyl-olefin metathesis has introduced a new means for revealing the behavior of Lewis acids. In particular, this reaction has led to the observation of new solution behaviors for FeCl3 that may qualitatively change how we think of Lewis acid activation. For example, catalytic metathesis reactions operate in the presence of superstoichiometric amounts of carbonyl, resulting in the formation of highly ligated (octahedral) iron geometries. These structures display reduced activity, decreasing catalyst turnover. As a result, it is necessary to steer the Fe-center away from inhibiting pathways to improve the reaction efficiency and augment yields for recalcitrant substrates. Herein, we examine the impact of the addition of TMSCl to FeCl3-catalyzed carbonyl-olefin metathesis, specifically for substrates that are prone to byproduct inhibition. Through kinetic, spectroscopic, and colligative experiments, significant deviations from the baseline metathesis reactivity are observed, including mitigation of byproduct inhibition as well as an increase in the reaction rate. Quantum chemical simulations are used to explain how TMSCl induces a change in catalyst structure that leads to these kinetic differences. Collectively, these data are consistent with the formation of a silylium catalyst, which induces the reaction through carbonyl binding. The FeCl3 activation of Si-Cl bonds to give the silylium active species is expected to have significant utility in enacting carbonyl-based transformations.
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Affiliation(s)
- Sophi R Todtz
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Cory W Schneider
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Tanmay Malakar
- Department of Chemistry, Barasat College, 10 K.N.C. Road, Barasat, Kolkata 700124, West Bengal, India
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Clare Anderson
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Heather Koska
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - James J Devery
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
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12
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Abstract
Machine learning models are increasingly being utilized to predict outcomes of organic chemical reactions. A large amount of reaction data is used to train these models, which is in stark contrast to how expert chemists discover and develop new reactions by leveraging information from a small number of relevant transformations. Transfer learning and active learning are two strategies that can operate in low-data situations, which may help fill this gap and promote the use of machine learning for tackling real-world challenges in organic synthesis. This Perspective introduces active and transfer learning and connects these to potential opportunities and directions for further research, especially in the area of prospective development of chemical transformations.
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Affiliation(s)
- Eunjae Shim
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ambuj Tewari
- Department of Statistics, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Tim Cernak
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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13
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Douthwaite JL, Zhao R, Shim E, Mahjour B, Zimmerman PM, Cernak T. Formal Cross-Coupling of Amines and Carboxylic Acids to Form sp 3-sp 2 Carbon-Carbon Bonds. J Am Chem Soc 2023; 145:10930-10937. [PMID: 37184831 DOI: 10.1021/jacs.2c11563] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Amines and carboxylic acids are abundant synthetic building blocks that are classically united to form an amide bond. To access new pockets of chemical space, we are interested in the development of amine-acid coupling reactions that complement the amide coupling. In particular, the formation of carbon-carbon bonds by formal deamination and decarboxylation would be an impactful addition to the synthesis toolbox. Here, we report a formal cross-coupling of alkyl amines and aryl carboxylic acids to form C(sp3)-C(sp2) bonds following preactivation of the amine-acid building blocks as a pyridinium salt and N-acyl-glutarimide, respectively. Under nickel-catalyzed reductive cross-coupling conditions, a diversity of simple and complex substrates are united in good to excellent yield, and numerous pharmaceuticals are successfully diversified. High-throughput experimentation was leveraged in the development of the reaction and the discovery of performance-enhancing additives such as phthalimide, RuCl3, and GaCl3. Mechanistic investigations suggest phthalimide may play a role in stabilizing productive Ni complexes rather than being involved in oxidative addition of the N-acyl-imide and that RuCl3 supports the decarbonylation event, thereby improving reaction selectivity.
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Affiliation(s)
- James L Douthwaite
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ruheng Zhao
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Eunjae Shim
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Babak Mahjour
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Tim Cernak
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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14
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Abstract
Heat-bath configuration interaction (HCI) is a deterministic method that approaches the full CI limit at greatly reduced computational cost. In this work, computational improvements to the HCI algorithm are introduced targeting speed, parallel efficiency, and memory requirements. The new implementation introduces a hash function to distribute determinants and takes advantage of MPI and OpenMP for parallelism allowing for a (22e,168o) active space to be studied, which explicitly includes 2.39 × 107 variational determinants and 8.95 × 1010 perturbative determinants. Benchmarks show up to 86% parallel efficiency of the perturbative step on 32 nodes (4096 cores) and a total efficiency of 74%. The new HCI implementation is benchmarked for accuracy against prior results and applied to study the triplet-quintet gap in the challenging [FeO(NH3)5]2+ complex.
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Affiliation(s)
- Duy-Khoi Dang
- Department of Chemistry, University of Michigan 930 North University Avenue Ann Arbor, Michigan 48109, United States
| | - Joshua A Kammeraad
- Department of Chemistry, University of Michigan 930 North University Avenue Ann Arbor, Michigan 48109, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan 930 North University Avenue Ann Arbor, Michigan 48109, United States
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15
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Hannigan MD, Tami JL, Zimmerman PM, McNeil AJ. Rethinking Catalyst Trapping in Ni-Catalyzed Thieno[3,2- b]thiophene Polymerization. Macromolecules 2022; 55:10821-10830. [PMID: 37396500 PMCID: PMC10312364 DOI: 10.1021/acs.macromol.2c01521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Catalyst-transfer polymerization (CTP) is a chain-growth method used to synthesize conjugated polymers. Although CTP works well for most donor-type monomers, the polymerization stalls with thieno[3,2-b]thiophene when using Ni catalysts. Previous reports have rationalized this result by suggesting that the catalyst is trapped in a Ni0 π-complex with the highly electron-rich arene. In this study, evidence is provided that the catalyst trap is more likely a NiII complex that arises from oxidative insertion of Ni0 into the C-S bonds of thieno[3,2-b]thiophene. This result is consistent with the known reactivity of Ni0 complexes toward S-heteroarenes and is supported herein by 31P nuclear magnetic resonance spectra acquired in situ, as well as data collected from small-molecule model reactions and density-functional theory simulations of the polymerization. We propose that this C-S insertion pathway and related off-cycle reactions may be relevant to understanding or enabling the CTP of other monomers with fused thiophenes.
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Affiliation(s)
- Matthew D Hannigan
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Jessica L Tami
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Anne J McNeil
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States; Macromolecular Science and Engineering Program, University of Michigan, Ann Arbor, Michigan 48109-2800, United States
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16
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Robo MT, Frank AR, Butler E, Nett AJ, Cañellas S, Zimmerman PM, Montgomery J. Activation Mechanism of Nickel(0) N-Heterocyclic Carbene Catalysts Stabilized by Fumarate Ligands. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michael T. Robo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Amie R. Frank
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Ellen Butler
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Alex J. Nett
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Santiago Cañellas
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - John Montgomery
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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17
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Jiang R, Gogineni T, Kammeraad J, He Y, Tewari A, Zimmerman PM. Conformer-RL: A deep reinforcement learning library for conformer generation. J Comput Chem 2022; 43:1880-1886. [PMID: 36000759 PMCID: PMC9542157 DOI: 10.1002/jcc.26984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/21/2022] [Accepted: 07/31/2022] [Indexed: 11/21/2022]
Abstract
Conformer‐RL is an open‐source Python package for applying deep reinforcement learning (RL) to the task of generating a diverse set of low‐energy conformations for a single molecule. The library features a simple interface to train a deep RL conformer generation model on any covalently bonded molecule or polymer, including most drug‐like molecules. Under the hood, it implements state‐of‐the‐art RL algorithms and graph neural network architectures tuned specifically for molecular structures. Conformer‐RL is also a platform for researching new algorithms and neural network architectures for conformer generation, as the library contains modular class interfaces for RL environments and agents, allowing users to easily swap components with their own implementations. Additionally, it comes with tools to visualize and save generated conformers for further analysis. Conformer‐RL is well‐tested and thoroughly documented with tutorials for each of the functionalities mentioned above, and is available on PyPi and Github: https://github.com/ZimmermanGroup/conformer-rl.
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Affiliation(s)
- Runxuan Jiang
- Department of EECS, University of Michigan, Ann Arbor, Michigan, USA
| | - Tarun Gogineni
- Department of EECS, University of Michigan, Ann Arbor, Michigan, USA
| | - Joshua Kammeraad
- Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA.,Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Yifei He
- Department of EECS, University of Michigan, Ann Arbor, Michigan, USA
| | - Ambuj Tewari
- Department of EECS, University of Michigan, Ann Arbor, Michigan, USA.,Department of Statistics, University of Michigan, Ann Arbor, Michigan, USA
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
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18
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Dang DK, Wilson LW, Zimmerman PM. The numerical evaluation of Slater integrals on graphics processing units. J Comput Chem 2022; 43:1680-1689. [PMID: 35861566 DOI: 10.1002/jcc.26968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 05/13/2022] [Accepted: 06/27/2022] [Indexed: 11/11/2022]
Abstract
This article presents SlaterGPU, a graphics processing unit (GPU) accelerated library that uses OpenACC to numerically compute Slater-type orbital (STO) integrals. The electron repulsion integrals (ERI) are computed under the RI approximation using the Coulomb potential of the Slater basis function. To fully realize the performance capabilities of modern GPUs, the Slater integrals are evaluated in mixed-precision, resulting in speedups for the ERIs of over 80×. Parallelization on multiple GPUs allows for integral throughput of over 3 million integrals per second. This places STO integral throughput within reach of single-threaded, conventional Gaussian integration schemes. To test the quality of the integrals, the fluorine exchange reaction barrier in fluoromethane was computed using heat-bath configuration interaction (HBCI). In addition, the singlet-triplet gap of cyclobutadiene was examined using HBCI in a triple- ζ $$ \zeta $$ , polarized basis set. These benchmarks demonstrate the library's ability to generate the full set of integrals necessary for configuration interaction with up to 6 h $$ 6h $$ functions in the auxiliary basis.
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Affiliation(s)
- Duy-Khoi Dang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Leighton W Wilson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA.,Department of Mathematics, University of Michigan, Ann Arbor, Michigan, USA
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
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19
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Shim E, Kammeraad JA, Xu Z, Tewari A, Cernak T, Zimmerman PM. Predicting reaction conditions from limited data through active transfer learning. Chem Sci 2022; 13:6655-6668. [PMID: 35756521 PMCID: PMC9172577 DOI: 10.1039/d1sc06932b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 05/10/2022] [Indexed: 12/30/2022] Open
Abstract
Transfer and active learning have the potential to accelerate the development of new chemical reactions, using prior data and new experiments to inform models that adapt to the target area of interest. This article shows how specifically tuned machine learning models, based on random forest classifiers, can expand the applicability of Pd-catalyzed cross-coupling reactions to types of nucleophiles unknown to the model. First, model transfer is shown to be effective when reaction mechanisms and substrates are closely related, even when models are trained on relatively small numbers of data points. Then, a model simplification scheme is tested and found to provide comparative predictivity on reactions of new nucleophiles that include unseen reagent combinations. Lastly, for a challenging target where model transfer only provides a modest benefit over random selection, an active transfer learning strategy is introduced to improve model predictions. Simple models, composed of a small number of decision trees with limited depths, are crucial for securing generalizability, interpretability, and performance of active transfer learning.
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Affiliation(s)
- Eunjae Shim
- Department of Chemistry, University of MichiganAnn ArborMIUSA
| | - Joshua A. Kammeraad
- Department of Chemistry, University of MichiganAnn ArborMIUSA,Department of Statistics, University of MichiganAnn ArborMIUSA
| | - Ziping Xu
- Department of Statistics, University of MichiganAnn ArborMIUSA
| | - Ambuj Tewari
- Department of Statistics, University of MichiganAnn ArborMIUSA,Department of Electrical Engineering and Computer Science, University of MichiganAnn ArborMIUSA
| | - Tim Cernak
- Department of Chemistry, University of MichiganAnn ArborMIUSA,Department of Medicinal Chemistry, University of MichiganAnn ArborMIUSA
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20
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Alam B, Jiang H, Zimmerman PM, Herbert JM. State-specific solvation for restricted active space spin-flip (RAS-SF) wave functions based on the polarizable continuum formalism. J Chem Phys 2022; 156:194110. [PMID: 35597663 DOI: 10.1063/5.0091636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The restricted active space spin-flip (RAS-SF) formalism is a particular form of single-reference configuration interaction that can describe some forms of strong correlation at a relatively low cost and which has recently been formulated for the description of charge-transfer excited states. Here, we introduce both equilibrium and nonequilibrium versions of a state-specific solvation correction for vertical transition energies computed using RAS-SF wave functions, based on the framework of a polarizable continuum model (PCM). Ground-state polarization is described using the solvent's static dielectric constant and in the nonequilibrium solvation approach that polarization is modified upon vertical excitation using the solvent's optical dielectric constant. Benchmark calculations are reported for well-studied models of photo-induced charge transfer, including naphthalene dimer, C2H4⋯C2F4, pentacene dimer, and perylene diimide (PDI) dimer, several of which are important in organic photovoltaic applications. For the PDI dimer, we demonstrate that the charge-transfer character of the excited states is enhanced in the presence of a low-dielectric medium (static dielectric constant ɛ0 = 3) as compared to a gas-phase calculation (ɛ0 = 1). This stabilizes mechanistic traps for singlet fission and helps to explain experimental singlet fission rates. We also examine the effects of nonequilibrium solvation on charge-separated states in an intramolecular singlet fission chromophore, where we demonstrate that the energetic ordering of the states changes as a function of solvent polarity. The RAS-SF + PCM methodology that is reported here provides a framework to study charge-separated states in solution and in photovoltaic materials.
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Affiliation(s)
- Bushra Alam
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Hanjie Jiang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - John M Herbert
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
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21
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Martin JL, Sati GC, Malakar T, Hatt J, Zimmerman PM, Montgomery J. Glycosyl Exchange of Unactivated Glycosidic Bonds: Suppressing or Embracing Side Reactivity in Catalytic Glycosylations. J Org Chem 2022; 87:5817-5826. [PMID: 35413188 PMCID: PMC9173671 DOI: 10.1021/acs.joc.2c00132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
While developing boron-catalyzed glycosylations using glycosyl fluoride donors and trialkylsilyl ether acceptors, competing pathways involving productive glycosylation or glycosyl exchange were observed. Experimental and computational mechanistic studies suggest a novel mode of reactivity where a dioxolenium ion is a key intermediate that promotes both pathways through addition to either a silyl ether or to the acetal of an existing glycosidic linkage. Modifications in catalyst structure enable either pathway to be favored, and with this understanding, improved multicomponent iterative couplings and glycosyl exchange processes were demonstrated.
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Affiliation(s)
- Joshua L Martin
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Girish C Sati
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Tanmay Malakar
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Jessica Hatt
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - John Montgomery
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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22
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Jackman KMK, Liang G, Boyle PD, Zimmerman PM, Blacquiere JM. Changes in ligand coordination mode induce bimetallic C-C coupling pathways. Dalton Trans 2022; 51:3977-3991. [PMID: 35174382 PMCID: PMC8937615 DOI: 10.1039/d2dt00322h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon-carbon coupling is one of the most powerful tools in the organic synthesis arsenal. Known methodologies primarily exploit monometallic Pd0/PdII catalytic mechanisms to give new C-C bonds. Bimetallic C-C coupling mechanisms that involve a PdI/PdII redox cycle, remain underexplored. Thus, a detailed mechnaistic understanding is imperative for the development of new bimetallic catalysts. Previously, a PdII-Me dimer (1) supported by L1, which has phosphine and 1-azaallyl donor groups, underwent reductive elimination to give ethane, a PdI dimer, a PdII monometallic complex, and Pd black. Herein, a comprehensive experimental and computational study of the reactivity of 1 is presented, which reveals that the versatile coordination chemistry of L1 promotes bimetallic C-C bond formation. The phosphine 1-azaallyl ligand adopts various bridging modes to maintain the bimetallic structure throughout the C-C bond forming mechanism, which involves intramolecular methyl transfer and 1,1-reductive elimination from one of the palladium atoms. The minor byproduct, methane, likely forms through a monometallic intermediate that is sensitive to solvent C-H activation. Overall, the capacity of L1 to adopt different coordination modes promotes the bimetallic C-C coupling channel through pathways that are unattainable with statically-coordinated ligands.
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Affiliation(s)
- Kyle M K Jackman
- Department of Chemistry, University of Western Ontario, London, Canada, N6A 5B7.
| | - Guangchao Liang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
| | - Paul D Boyle
- Department of Chemistry, University of Western Ontario, London, Canada, N6A 5B7.
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
| | - Johanna M Blacquiere
- Department of Chemistry, University of Western Ontario, London, Canada, N6A 5B7.
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23
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Robo MT, Collias D, Zimmerman PM. Interplay Between Applied Force and Radical Attack in the Mechanochemical Chain Scission of Poly(acrylic acid). J Phys Chem A 2022; 126:521-528. [PMID: 35078315 DOI: 10.1021/acs.jpca.1c08919] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sonication and radical attack are both known to contribute to breaking down polymers. Quantum chemical models show how the two can operate together, where radical attack is shown to reduce the effective tensile strength of the material. Using poly(acrylic acid) (PAA) as a model, hydrogen atom abstraction in PAA was found to improve the thermodynamics and kinetics of bond scission. The force needed for bond rupture was estimated to decrease from 4.7 to 2.5 nN. This occurs because hydrogen atom abstraction drastically alters the potential energy surface of the scissile bond. Bond activation was also found to decrease the magnitude of the changes in bond scission geometries and energetics in response to the applied force. While radical abstraction is overall beneficial for mechanical bond scission, the polymer also becomes less responsive to force than the unactivated polymer. This finding places upper limits on the efficacy of the synergy between radical attack and applied force. In addition, the importance of reaction pathway optimization is also shown, where comparisons to the COGEF method show the latter to be qualitatively incapable of describing chain scission after radical activation.
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Affiliation(s)
- Michael T Robo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48104, United States
| | - Dimitris Collias
- Corporate R&D, The Procter and Gamble Co., West Chester, Ohio 45069, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48104, United States
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24
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Shao W, Jiang H, Ansari R, Zimmerman PM, Kim J. Heavy atom oriented orbital angular momentum manipulation in metal-free organic phosphors. Chem Sci 2022; 13:789-797. [PMID: 35173944 PMCID: PMC8768842 DOI: 10.1039/d1sc05689a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/15/2021] [Indexed: 01/31/2023] Open
Abstract
Metal-free purely organic phosphors (POPs) are emerging materials for display technologies, solid-state lighting, and chemical sensors. However, due to limitations in contemporary design strategies, the intrinsic spin-orbit coupling (SOC) efficiency of POPs remains low and their emission lifetime is pinned in the millisecond regime. Here, we present a design concept for POPs where the two main factors that control SOC-the heavy atom effect and orbital angular momentum-are tightly coupled to maximize SOC. This strategy is bolstered by novel natural-transition-orbital-based computational methods to visualize and quantify angular momentum descriptors for molecular design. To demonstrate the effectiveness of this strategy, prototype POPs were created having efficient room-temperature phosphorescence with lifetimes pushed below the millisecond regime, which were enabled by boosted SOC efficiencies beyond 102 cm-1 and achieved record-high efficiencies in POPs. Electronic structure analysis shows how discrete tuning of heavy atom effects and orbital angular momentum is possible within the proposed design strategy, leading to a strong degree of control over the resulting POP properties.
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Affiliation(s)
- Wenhao Shao
- Department of Chemistry, Department of Chemical Engineering, Department of Materials Science and Engineering, Macromolecular Science and Engineering, University of Michigan Ann Arbor Michigan 48109 USA
| | - Hanjie Jiang
- Department of Chemistry, Department of Chemical Engineering, Department of Materials Science and Engineering, Macromolecular Science and Engineering, University of Michigan Ann Arbor Michigan 48109 USA
| | - Ramin Ansari
- Department of Chemistry, Department of Chemical Engineering, Department of Materials Science and Engineering, Macromolecular Science and Engineering, University of Michigan Ann Arbor Michigan 48109 USA
| | - Paul M Zimmerman
- Department of Chemistry, Department of Chemical Engineering, Department of Materials Science and Engineering, Macromolecular Science and Engineering, University of Michigan Ann Arbor Michigan 48109 USA
| | - Jinsang Kim
- Department of Chemistry, Department of Chemical Engineering, Department of Materials Science and Engineering, Macromolecular Science and Engineering, University of Michigan Ann Arbor Michigan 48109 USA
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25
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Abstract
Accurate exchange-correlation (XC) potentials for three-dimensional systems─via solution of the inverse density functional theory (DFT) problem─are now available to test the quality of DFT approximations. Herein, the exact XC potential for seven molecules─dihydrogen at four different bond-lengths, lithium hydride, water, and ortho-benzyne─are computed from full configuration interaction reference densities. These are compared to model XC potentials from nonlocal (B3LYP, HSE06, SCAN0, and M08-HX) and semilocal/local (SCAN, PBE, and PW92) XC functionals. Whereas for most systems, relative errors in the ground-state densities are O(10-3-10-2), the model XC potentials have much higher errors of O(10-1-100). Among the model XC functionals, SCAN0 offers the best agreement with the exact XC potential, underlining the significance of satisfying exact conditions as well as including nonlocal effects in XC functionals. This work indicates that tests against the exact XC potential will provide a promising new direction for building more accurate XC functionals for DFT.
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Affiliation(s)
- Bikash Kanungo
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Vikram Gavini
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
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26
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Wang S, Zhelavskyi O, Lee J, Argüelles AJ, Khomutnyk YY, Mensah E, Guo H, Hourani R, Zimmerman PM, Nagorny P. Studies of Catalyst-Controlled Regioselective Acetalization and Its Application to Single-Pot Synthesis of Differentially Protected Saccharides. J Am Chem Soc 2021; 143:18592-18604. [PMID: 34705439 PMCID: PMC8585716 DOI: 10.1021/jacs.1c08448] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This article describes studies on the regioselective acetal protection of monosaccharide-based diols using chiral phosphoric acids (CPAs) and their immobilized polymeric variants, (R)-Ad-TRIP-PS and (S)-SPINOL-PS, as the catalysts. These catalyst-controlled regioselective acetalizations were found to proceed with high regioselectivities (up to >25:1 rr) on various d-glucose-, d-galactose-, d-mannose-, and l-fucose-derived 1,2-diols and could be carried out in a regiodivergent fashion depending on the choice of chiral catalyst. The polymeric catalysts were conveniently recycled and reused multiple times for gram-scale functionalizations with catalytic loadings as low as 0.1 mol %, and their performance was often found to be superior to the performance of their monomeric variants. These regioselective CPA-catalyzed acetalizations were successfully combined with common hydroxyl group functionalizations as single-pot telescoped procedures to produce 32 regioisomerically pure differentially protected mono- and disaccharide derivatives. To further demonstrate the utility of the polymeric catalysts, the same batch of (R)-Ad-TRIP-PS catalyst was recycled and reused to accomplish single-pot gram-scale syntheses of 6 differentially protected d-glucose derivatives. The subsequent exploration of the reaction mechanism using NMR studies of deuterated and nondeuterated substrates revealed that low-temperature acetalizations happen via a syn-addition mechanism and that the reaction regioselectivity exhibits strong dependence on the temperature. The computational studies indicate a complex temperature-dependent interplay of two reaction mechanisms, one involving an anomeric phosphate intermediate and another via concerted asynchronous formation of an acetal, that results in syn-addition products. The computational models also explain the steric factors responsible for the observed C2 selectivities and are consistent with experimentally observed selectivity trends.
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Affiliation(s)
- Sibin Wang
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109
| | - Oleksii Zhelavskyi
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109
| | - Jeonghyo Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea
| | - Alonso J. Argüelles
- Synthetic Molecule Design and Development, Lilly Research Laboratories, Eli Lilly and Company, 307 E. Merrill St. Indianapolis, IN 46225
| | | | - Enoch Mensah
- Chemistry Department, Indiana University Southeast, 4201 Grant Line Rd. New Albany, IN 47150
| | - Hao Guo
- Deparment of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA 18015
| | - Rami Hourani
- Chemistry Department, Stanford University, 333 Campus Drive, Stanford, CA 94305-5080
| | - Paul M. Zimmerman
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109
| | - Pavel Nagorny
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109
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27
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Rivera Cruz KE, Liu Y, Soucy TL, Zimmerman PM, McCrory CCL. Increasing the CO2 Reduction Activity of Cobalt Phthalocyanine by Modulating the σ-Donor Strength of Axially Coordinating Ligands. ACS Catal 2021. [DOI: 10.1021/acscatal.1c02379] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Kevin E. Rivera Cruz
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Yingshuo Liu
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Taylor L. Soucy
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Charles C. L. McCrory
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
- Macromolecular Science and Engineering Program, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
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28
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Prajapati B, Dang D, Chmielewski PJ, Majewski MA, Lis T, Gómez‐García CJ, Zimmerman PM, Stępień M. An Open‐Shell Coronoid with Hybrid Chichibabin–Schlenk Conjugation. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202109273] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Bibek Prajapati
- Wydział Chemii Uniwersytet Wrocławski ul. F. Joliot-Curie 14 50-383 Wrocław Poland
| | - Duy‐Khoi Dang
- Department of Chemistry University of Michigan 930 N. University Ave Ann Arbor MI 48109 USA
| | - Piotr J. Chmielewski
- Wydział Chemii Uniwersytet Wrocławski ul. F. Joliot-Curie 14 50-383 Wrocław Poland
| | - Marcin A. Majewski
- Wydział Chemii Uniwersytet Wrocławski ul. F. Joliot-Curie 14 50-383 Wrocław Poland
| | - Tadeusz Lis
- Wydział Chemii Uniwersytet Wrocławski ul. F. Joliot-Curie 14 50-383 Wrocław Poland
| | - Carlos J. Gómez‐García
- Departamento de Química Inorgánica and Instituto de Ciencia Molecular Universidad de Valencia 46980 Paterna Spain
| | - Paul M. Zimmerman
- Department of Chemistry University of Michigan 930 N. University Ave Ann Arbor MI 48109 USA
| | - Marcin Stępień
- Wydział Chemii Uniwersytet Wrocławski ul. F. Joliot-Curie 14 50-383 Wrocław Poland
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Hannigan MD, McNeil AJ, Zimmerman PM. Using JPP to Identify Ni Bidentate Phosphine Complexes In Situ. Inorg Chem 2021; 60:13400-13408. [PMID: 34405991 DOI: 10.1021/acs.inorgchem.1c01720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Identifying intermediates of Ni-containing reactions can be challenging due to the high reactivity of Ni complexes and their sensitivity toward air and moisture. Many Ni bidentate phosphine complexes are diamagnetic and can be analyzed in situ via 31P NMR spectroscopy, but the oxidation state of Ni is difficult to determine using 31P chemical shift analysis alone. The J-coupling between P atoms, JPP, has been proposed to correlate with oxidation state, but few investigations have looked at how JPP is affected by parameters such as length of the linker or identity of the phosphine or other ligands. The present investigation into the JPP values of Ni bidentate phosphine complexes with two-carbon and three-carbon linkers shows that the JPP values observed in 31P NMR spectra, |JPP|, are competent indicators of the oxidation state at Ni. For complexes with two-carbon linkers, |JPP| > 40 Hz is typical of Ni0 while |JPP| < 30 Hz is typical of NiII; this trend is reversed for complexes with three-carbon linkers. Additionally, the Lewis acidity of the Ni and Lewis basicity of the phosphine ligand affect JPP predictably. For example, increased P-to-Ni donation arising from more-donating phosphines or more-withdrawing ligands trans to the P atoms causes a more negative JPP. These results should enable the oxidation state of Ni and properties of ligands in Ni bidentate phosphine complexes to be determined in situ during reactions containing these species.
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Affiliation(s)
- Matthew D Hannigan
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Anne J McNeil
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109-1055, United States.,Macromolecular Science and Engineering Program, University of Michigan, 2800 Plymouth Road, Ann Arbor, Michigan 48109-2800, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109-1055, United States
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30
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Epifanovsky E, Gilbert ATB, Feng X, Lee J, Mao Y, Mardirossian N, Pokhilko P, White AF, Coons MP, Dempwolff AL, Gan Z, Hait D, Horn PR, Jacobson LD, Kaliman I, Kussmann J, Lange AW, Lao KU, Levine DS, Liu J, McKenzie SC, Morrison AF, Nanda KD, Plasser F, Rehn DR, Vidal ML, You ZQ, Zhu Y, Alam B, Albrecht BJ, Aldossary A, Alguire E, Andersen JH, Athavale V, Barton D, Begam K, Behn A, Bellonzi N, Bernard YA, Berquist EJ, Burton HGA, Carreras A, Carter-Fenk K, Chakraborty R, Chien AD, Closser KD, Cofer-Shabica V, Dasgupta S, de Wergifosse M, Deng J, Diedenhofen M, Do H, Ehlert S, Fang PT, Fatehi S, Feng Q, Friedhoff T, Gayvert J, Ge Q, Gidofalvi G, Goldey M, Gomes J, González-Espinoza CE, Gulania S, Gunina AO, Hanson-Heine MWD, Harbach PHP, Hauser A, Herbst MF, Hernández Vera M, Hodecker M, Holden ZC, Houck S, Huang X, Hui K, Huynh BC, Ivanov M, Jász Á, Ji H, Jiang H, Kaduk B, Kähler S, Khistyaev K, Kim J, Kis G, Klunzinger P, Koczor-Benda Z, Koh JH, Kosenkov D, Koulias L, Kowalczyk T, Krauter CM, Kue K, Kunitsa A, Kus T, Ladjánszki I, Landau A, Lawler KV, Lefrancois D, Lehtola S, Li RR, Li YP, Liang J, Liebenthal M, Lin HH, Lin YS, Liu F, Liu KY, Loipersberger M, Luenser A, Manjanath A, Manohar P, Mansoor E, Manzer SF, Mao SP, Marenich AV, Markovich T, Mason S, Maurer SA, McLaughlin PF, Menger MFSJ, Mewes JM, Mewes SA, Morgante P, Mullinax JW, Oosterbaan KJ, Paran G, Paul AC, Paul SK, Pavošević F, Pei Z, Prager S, Proynov EI, Rák Á, Ramos-Cordoba E, Rana B, Rask AE, Rettig A, Richard RM, Rob F, Rossomme E, Scheele T, Scheurer M, Schneider M, Sergueev N, Sharada SM, Skomorowski W, Small DW, Stein CJ, Su YC, Sundstrom EJ, Tao Z, Thirman J, Tornai GJ, Tsuchimochi T, Tubman NM, Veccham SP, Vydrov O, Wenzel J, Witte J, Yamada A, Yao K, Yeganeh S, Yost SR, Zech A, Zhang IY, Zhang X, Zhang Y, Zuev D, Aspuru-Guzik A, Bell AT, Besley NA, Bravaya KB, Brooks BR, Casanova D, Chai JD, Coriani S, Cramer CJ, Cserey G, DePrince AE, DiStasio RA, Dreuw A, Dunietz BD, Furlani TR, Goddard WA, Hammes-Schiffer S, Head-Gordon T, Hehre WJ, Hsu CP, Jagau TC, Jung Y, Klamt A, Kong J, Lambrecht DS, Liang W, Mayhall NJ, McCurdy CW, Neaton JB, Ochsenfeld C, Parkhill JA, Peverati R, Rassolov VA, Shao Y, Slipchenko LV, Stauch T, Steele RP, Subotnik JE, Thom AJW, Tkatchenko A, Truhlar DG, Van Voorhis T, Wesolowski TA, Whaley KB, Woodcock HL, Zimmerman PM, Faraji S, Gill PMW, Head-Gordon M, Herbert JM, Krylov AI. Software for the frontiers of quantum chemistry: An overview of developments in the Q-Chem 5 package. J Chem Phys 2021; 155:084801. [PMID: 34470363 PMCID: PMC9984241 DOI: 10.1063/5.0055522] [Citation(s) in RCA: 412] [Impact Index Per Article: 137.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
This article summarizes technical advances contained in the fifth major release of the Q-Chem quantum chemistry program package, covering developments since 2015. A comprehensive library of exchange-correlation functionals, along with a suite of correlated many-body methods, continues to be a hallmark of the Q-Chem software. The many-body methods include novel variants of both coupled-cluster and configuration-interaction approaches along with methods based on the algebraic diagrammatic construction and variational reduced density-matrix methods. Methods highlighted in Q-Chem 5 include a suite of tools for modeling core-level spectroscopy, methods for describing metastable resonances, methods for computing vibronic spectra, the nuclear-electronic orbital method, and several different energy decomposition analysis techniques. High-performance capabilities including multithreaded parallelism and support for calculations on graphics processing units are described. Q-Chem boasts a community of well over 100 active academic developers, and the continuing evolution of the software is supported by an "open teamware" model and an increasingly modular design.
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Affiliation(s)
- Evgeny Epifanovsky
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | | | | | - Joonho Lee
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Yuezhi Mao
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | - Pavel Pokhilko
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Alec F. White
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Marc P. Coons
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Adrian L. Dempwolff
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Zhengting Gan
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | - Diptarka Hait
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Paul R. Horn
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Leif D. Jacobson
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | | | - Jörg Kussmann
- Department of Chemistry, Ludwig Maximilian University, Butenandtstr. 7, D-81377 München, Germany
| | - Adrian W. Lange
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Ka Un Lao
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Daniel S. Levine
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | - Simon C. McKenzie
- Research School of Chemistry, Australian National University, Canberra, Australia
| | | | - Kaushik D. Nanda
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | | | - Dirk R. Rehn
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Marta L. Vidal
- Department of Chemistry, Technical University of Denmark, Kemitorvet Bldg. 207, DK-2800 Kgs Lyngby, Denmark
| | | | - Ying Zhu
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Bushra Alam
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Benjamin J. Albrecht
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | | | - Ethan Alguire
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Josefine H. Andersen
- Department of Chemistry, Technical University of Denmark, Kemitorvet Bldg. 207, DK-2800 Kgs Lyngby, Denmark
| | - Vishikh Athavale
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Dennis Barton
- Department of Physics and Materials Science, University of Luxembourg, L-1511 Luxembourg, Luxembourg
| | - Khadiza Begam
- Department of Physics, Kent State University, Kent, Ohio 44242, USA
| | - Andrew Behn
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Nicole Bellonzi
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yves A. Bernard
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | | | - Hugh G. A. Burton
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Abel Carreras
- Donostia International Physics Center, 20080 Donostia, Euskadi, Spain
| | - Kevin Carter-Fenk
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | | | - Alan D. Chien
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | | - Vale Cofer-Shabica
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Saswata Dasgupta
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Marc de Wergifosse
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Jia Deng
- Research School of Chemistry, Australian National University, Canberra, Australia
| | | | - Hainam Do
- School of Chemistry, University of Nottingham, Nottingham, United Kingdom
| | - Sebastian Ehlert
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Beringstr. 4, 53115 Bonn, Germany
| | - Po-Tung Fang
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | | | - Qingguo Feng
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44240, USA
| | - Triet Friedhoff
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - James Gayvert
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA
| | - Qinghui Ge
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Gergely Gidofalvi
- Department of Chemistry and Biochemistry, Gonzaga University, Spokane, Washington 99258, USA
| | - Matthew Goldey
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Joe Gomes
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | - Sahil Gulania
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Anastasia O. Gunina
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | | | - Phillip H. P. Harbach
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Andreas Hauser
- Institute of Experimental Physics, Graz University of Technology, Graz, Austria
| | | | - Mario Hernández Vera
- Department of Chemistry, Ludwig Maximilian University, Butenandtstr. 7, D-81377 München, Germany
| | - Manuel Hodecker
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Zachary C. Holden
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Shannon Houck
- Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - Xunkun Huang
- Department of Chemistry, Xiamen University, Xiamen 361005, China
| | - Kerwin Hui
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Bang C. Huynh
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Maxim Ivanov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Ádám Jász
- Stream Novation Ltd., Práter utca 50/a, H-1083 Budapest, Hungary
| | - Hyunjun Ji
- Graduate School of Energy, Environment, Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hanjie Jiang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Benjamin Kaduk
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Sven Kähler
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Kirill Khistyaev
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Jaehoon Kim
- Graduate School of Energy, Environment, Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Gergely Kis
- Stream Novation Ltd., Práter utca 50/a, H-1083 Budapest, Hungary
| | | | - Zsuzsanna Koczor-Benda
- Department of Chemistry, Ludwig Maximilian University, Butenandtstr. 7, D-81377 München, Germany
| | - Joong Hoon Koh
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Dimitri Kosenkov
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Laura Koulias
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | | | - Caroline M. Krauter
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Karl Kue
- Institute of Chemistry, Academia Sinica, 128, Academia Road Section 2, Nangang District, Taipei 11529, Taiwan
| | - Alexander Kunitsa
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA
| | - Thomas Kus
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | | | - Arie Landau
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Keith V. Lawler
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Daniel Lefrancois
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | | | - Run R. Li
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Yi-Pei Li
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Jiashu Liang
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Marcus Liebenthal
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Hung-Hsuan Lin
- Institute of Chemistry, Academia Sinica, 128, Academia Road Section 2, Nangang District, Taipei 11529, Taiwan
| | - You-Sheng Lin
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Fenglai Liu
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | | | | | - Arne Luenser
- Department of Chemistry, Ludwig Maximilian University, Butenandtstr. 7, D-81377 München, Germany
| | - Aaditya Manjanath
- Institute of Chemistry, Academia Sinica, 128, Academia Road Section 2, Nangang District, Taipei 11529, Taiwan
| | - Prashant Manohar
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Erum Mansoor
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Sam F. Manzer
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Shan-Ping Mao
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | | | - Thomas Markovich
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Stephen Mason
- School of Chemistry, University of Nottingham, Nottingham, United Kingdom
| | - Simon A. Maurer
- Department of Chemistry, Ludwig Maximilian University, Butenandtstr. 7, D-81377 München, Germany
| | - Peter F. McLaughlin
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | | | - Jan-Michael Mewes
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Stefanie A. Mewes
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Pierpaolo Morgante
- Department of Chemistry, Florida Institute of Technology, Melbourne, Florida 32901, USA
| | - J. Wayne Mullinax
- Department of Chemistry, Florida Institute of Technology, Melbourne, Florida 32901, USA
| | | | | | - Alexander C. Paul
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Suranjan K. Paul
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Fabijan Pavošević
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Zheng Pei
- School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Stefan Prager
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Emil I. Proynov
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | - Ádám Rák
- Stream Novation Ltd., Práter utca 50/a, H-1083 Budapest, Hungary
| | - Eloy Ramos-Cordoba
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Bhaskar Rana
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Alan E. Rask
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Adam Rettig
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Ryan M. Richard
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Fazle Rob
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | - Elliot Rossomme
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Tarek Scheele
- Institute for Physical and Theoretical Chemistry, University of Bremen, Bremen, Germany
| | - Maximilian Scheurer
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Matthias Schneider
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Nickolai Sergueev
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44240, USA
| | - Shaama M. Sharada
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Wojciech Skomorowski
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - David W. Small
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Christopher J. Stein
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Yu-Chuan Su
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Eric J. Sundstrom
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Zhen Tao
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Jonathan Thirman
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Gábor J. Tornai
- Stream Novation Ltd., Práter utca 50/a, H-1083 Budapest, Hungary
| | - Takashi Tsuchimochi
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Norm M. Tubman
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | - Oleg Vydrov
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jan Wenzel
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Jon Witte
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Atsushi Yamada
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44240, USA
| | - Kun Yao
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Sina Yeganeh
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Shane R. Yost
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Alexander Zech
- Department of Physical Chemistry, University of Geneva, 30, Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland
| | - Igor Ying Zhang
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Xing Zhang
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Yu Zhang
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | - Dmitry Zuev
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Alán Aspuru-Guzik
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Alexis T. Bell
- Department of Chemical Engineering, University of California, Berkeley, California 94720, USA
| | - Nicholas A. Besley
- School of Chemistry, University of Nottingham, Nottingham, United Kingdom
| | - Ksenia B. Bravaya
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA
| | - Bernard R. Brooks
- Laboratory of Computational Biophysics, National Institute of Health, Bethesda, Maryland 20892, USA
| | - David Casanova
- Donostia International Physics Center, 20080 Donostia, Euskadi, Spain
| | | | - Sonia Coriani
- Department of Chemistry, Technical University of Denmark, Kemitorvet Bldg. 207, DK-2800 Kgs Lyngby, Denmark
| | | | | | - A. Eugene DePrince
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Robert A. DiStasio
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Barry D. Dunietz
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44240, USA
| | - Thomas R. Furlani
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
| | - William A. Goddard
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125, USA
| | | | - Teresa Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | | | | | - Yousung Jung
- Graduate School of Energy, Environment, Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Andreas Klamt
- COSMOlogic GmbH & Co. KG, Imbacher Weg 46, D-51379 Leverkusen, Germany
| | - Jing Kong
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
| | - Daniel S. Lambrecht
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | | | | | - C. William McCurdy
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Jeffrey B. Neaton
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Christian Ochsenfeld
- Department of Chemistry, Ludwig Maximilian University, Butenandtstr. 7, D-81377 München, Germany
| | - John A. Parkhill
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Roberto Peverati
- Department of Chemistry, Florida Institute of Technology, Melbourne, Florida 32901, USA
| | - Vitaly A. Rassolov
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA
| | | | | | | | - Ryan P. Steele
- Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
| | - Joseph E. Subotnik
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Alex J. W. Thom
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Alexandre Tkatchenko
- Department of Physics and Materials Science, University of Luxembourg, L-1511 Luxembourg, Luxembourg
| | - Donald G. Truhlar
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Troy Van Voorhis
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Tomasz A. Wesolowski
- Department of Physical Chemistry, University of Geneva, 30, Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland
| | - K. Birgitta Whaley
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - H. Lee Woodcock
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, USA
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Shirin Faraji
- Zernike Institute for Advanced Materials, University of Groningen, 9774AG Groningen, The Netherlands
| | | | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - John M. Herbert
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Anna I. Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA,Author to whom correspondence should be addressed:
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31
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Stępień M, Prajapati B, Dang DK, Chmielewski PJ, Majewski MA, Lis T, Gómez-García CJ, Zimmerman PM. An Open-Shell Coronoid with Hybrid Chichibabin-Schlenk Conjugation. Angew Chem Int Ed Engl 2021; 60:22496-22504. [PMID: 34382721 DOI: 10.1002/anie.202109273] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 07/30/2021] [Indexed: 11/10/2022]
Abstract
A hexaradicaloid molecule with alternating Kekulé and non-Kekulé connectivities between adjacent spin centers was obtained by fusing two classic conjugation motifs, found respectively in the Chichibabin and Schlenk hydrocarbons, into a coronoid structure. 1 H NMR, ESR and SQUID experiments, combined with computational analyses reveal that the system has a singlet ground state, characterized by a significant hexaradicaloid character ( γ 0 = 0.826, γ 1 = γ 2 = 0.773). It possesses multiple thermally accessible high-spin states (up to the septet), with uniform energy gaps of ca 1.0 kcal/mol between consecutive multiplicities. In line with its open-shell character, the coronoid has a small electronic bandgap of ca. 0.8 eV and undergoes two consecutive one-electron oxidations at low potentials, yielding cationic forms with extended near-infrared absorption. The hexaradicaloid, which combines open-shell and macrocyclic contributions to its π conjugation, provides an example of a design strategy for multistate spin switches and redox-amphoteric NIR dyes.
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Affiliation(s)
- Marcin Stępień
- University of Wroclaw, Department of Chemistry, ul. F. Joliot-Curie 14, 50-383, Wroclaw, POLAND
| | | | - Duy-Khoi Dang
- University of Michigan Ann Arbor, Department of Chemistry, UNITED STATES
| | | | | | - Tadeusz Lis
- Uniwersytet Wrocławski, Wydział Chemii, POLAND
| | - Carlos J Gómez-García
- Universidad de Valencia, Departamento de Química Inorgánica and Instituto de Ciencia Molecular, SPAIN
| | - Paul M Zimmerman
- University of Michigan Ann Arbor, Department of Chemistry, UNITED STATES
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32
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Chazovachii PT, Somers MJ, Robo MT, Collias DI, James MI, Marsh ENG, Zimmerman PM, Alfaro JF, McNeil AJ. Giving superabsorbent polymers a second life as pressure-sensitive adhesives. Nat Commun 2021; 12:4524. [PMID: 34312375 PMCID: PMC8313680 DOI: 10.1038/s41467-021-24488-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 06/22/2021] [Indexed: 11/08/2022] Open
Abstract
An estimated 6.3 billion metric tons of post-consumer polymer waste has been produced, with the majority (79%) in landfills or the environment. Recycling methods that utilize these waste polymers could attenuate their environmental impact. For many polymers, recycling via mechanical processes is not feasible and these materials are destined for landfills or incineration. One salient example is the superabsorbent material used in diapers and feminine hygiene products, which contain crosslinked sodium polyacrylates. Here we report an open-loop recycling method for these materials that involves (i) decrosslinking via hydrolysis, (ii) an optional chain-shortening via sonication, and (iii) functionalizing via Fischer esterification. The resulting materials exhibit low-to-medium storage and loss moduli, and as such, are applicable as general-purpose adhesives. A life cycle assessment demonstrates that the adhesives synthesized via this approach outcompete the same materials derived from petroleum feedstocks on nearly every metric, including carbon dioxide emissions and cumulative energy demand.
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Affiliation(s)
| | - Madeline J Somers
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
| | - Michael T Robo
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Dimitris I Collias
- Materials Science Innovation-Corporate R&D, The Procter & Gamble Co., West Chester, OH, USA
| | - Martin I James
- Materials Science Innovation-Corporate R&D, The Procter & Gamble Co., West Chester, OH, USA
| | - E Neil G Marsh
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Jose F Alfaro
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
| | - Anne J McNeil
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA.
- Macromolecular Science and Engineering Program, University of Michigan, Ann Arbor, MI, USA.
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33
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Yang X, Gitter SR, Roessler AG, Zimmerman PM, Boydston AJ. An Ion-Pairing Approach to Stereoselective Metal-Free Ring-Opening Metathesis Polymerization. Angew Chem Int Ed Engl 2021; 60:13952-13958. [PMID: 33723902 DOI: 10.1002/anie.202016393] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/25/2021] [Indexed: 11/08/2022]
Abstract
Stereochemistry can have a profound impact on polymer and materials properties. Unfortunately, straightforward methods for realizing high levels of stereocontrolled polymerizations are often challenging to achieve. In a departure from traditional metal-mediated ring-opening metathesis polymerization (ROMP), we discovered a remarkably simple method for controlling alkene stereochemistry in photoredox mediated metal-free ROMP. Ion-pairing, initiator sterics, and solvation effects each had profound impact on the stereochemistry of polynorbornene (PNB). Simple modifications to the reaction conditions produced PNB with trans alkene content of 25 to >98 %. High cis content was obtained from relatively larger counterions, toluene as solvent, low temperatures (-78 °C), and initiators with low Charton values. Conversely, smaller counterions, dichloromethane as solvent, and enol ethers with higher Charton values enabled production of PNB with high trans content. Data from a combined experimental and computational investigation are consistent with the stereocontrolling step of the radical cationic mechanism proceeding under thermodynamic control.
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Affiliation(s)
- Xuejin Yang
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Sean R Gitter
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Allison G Roessler
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Chemistry, Oglethorpe University, Atlanta, GA, 30319, USA
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Andrew J Boydston
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.,Department of Chemical and Biological Engineering, Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
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34
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Shen H, Larsen MB, Roessler AG, Zimmerman PM, Boydston AJ. Mechanochemical Release of N-Heterocyclic Carbenes from Flex-Activated Mechanophores. Angew Chem Int Ed Engl 2021; 60:13559-13563. [PMID: 33826803 DOI: 10.1002/anie.202100576] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/25/2021] [Indexed: 11/09/2022]
Abstract
We have discovered a new flex-activated mechanophore that releases an N-heterocyclic carbene (NHC) under mechanical load. The mechanophore design is based upon NHC-carbodiimide (NHC-CDI) adducts and demonstrates an important first step toward flex-activated designs capable of further downstream reactivities. Since the flex-activation is non-destructive to the main polymer chains, the material can be subjected to multiple compression cycles to achieve iterative increases in the activation percentage of mechanophores. Two different NHC structures were demonstrated, signifying the potential modularity of the mechanophore design.
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Affiliation(s)
- Hang Shen
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI, 53706, USA
| | - Michael B Larsen
- Department of Materials Science and Engineering, Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.,Department of Chemistry, Western Washington University, Bellingham, WA, 98225, USA
| | - Allison G Roessler
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI, 48109, USA.,Department of Chemistry, Oglethorpe University, 4484 Peachtree Rd, Atlanta, GA, 30319, USA
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI, 48109, USA
| | - Andrew J Boydston
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI, 53706, USA.,Department of Materials Science and Engineering, Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.,Department of Chemistry, Western Washington University, Bellingham, WA, 98225, USA
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35
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Shen H, Larsen MB, Roessler AG, Zimmerman PM, Boydston AJ. Mechanochemical Release of
N
‐Heterocyclic Carbenes from Flex‐Activated Mechanophores. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Hang Shen
- Department of Chemistry University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
| | - Michael B. Larsen
- Department of Materials Science and Engineering Department of Chemical and Biological Engineering University of Wisconsin-Madison Madison WI 53706 USA
- Department of Chemistry Western Washington University Bellingham WA 98225 USA
| | - Allison G. Roessler
- Department of Chemistry University of Michigan 930 N. University Ave Ann Arbor MI 48109 USA
- Department of Chemistry Oglethorpe University 4484 Peachtree Rd Atlanta GA 30319 USA
| | - Paul M. Zimmerman
- Department of Chemistry University of Michigan 930 N. University Ave Ann Arbor MI 48109 USA
| | - Andrew J. Boydston
- Department of Chemistry University of Wisconsin-Madison 1101 University Avenue Madison WI 53706 USA
- Department of Materials Science and Engineering Department of Chemical and Biological Engineering University of Wisconsin-Madison Madison WI 53706 USA
- Department of Chemistry Western Washington University Bellingham WA 98225 USA
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36
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Muthike AK, Carlotti B, Madu IK, Jiang H, Kim H, Wu Q, Yu L, Zimmerman PM, Goodson T. The Role of the Core Attachment Positioning in Triggering Intramolecular Singlet Exciton Fission in Perylene Diimide Tetramers. J Phys Chem B 2021; 125:5114-5131. [PMID: 33961426 DOI: 10.1021/acs.jpcb.1c02534] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previous studies have proposed that the presence of a flexible π-bridge linker is crucial in activating intramolecular singlet exciton fission (iSEF) in multichromophoric systems. In this study, we report the photophysical properties of three analogous perylene diimide (PDI) dendritic tetramers showing flexible/twisted π-bridged structures with α- and β-substitutions and a rigid/planar structure with a β-fused ring (βC) connection to a benzodithiophene-thiophene (BDT-Th) core. The rigidity and enhanced planarity of βC lead to significant intramolecular charge transfer and triplet formation via an intersystem crossing pathway. Steady-state spectroscopic measurements reveal similar absorption and emission spectra for the α-tetramer and the parent PDI monomer. However, their fluorescence quantum yield is significantly different. The negligible fluorescence yield of the α-tetramer (0.04%) is associated with a competitive nonradiative decay pathway. Indeed, for this twisted compound in a high polar environment, a fast and efficient iSEF with a triplet quantum yield of 124% is observed. Our results show that the α-single-bond connections in the α compound are capable of interrupting the coupling among the PDI units, favoring iSEF. We propose that the formation of the double triplet (1[TT]) state is through a superposition of singlet states known as [S1S0][TT]CT, which has been suggested previously for pentacene derivatives. Using steady-state and time-resolved spectroscopic experiments, we demonstrate that the conformational flexibility of the linker itself is necessary but not sufficient to allow iSEF. For the case of the other twisted tetramer, β, the strong π-π co-facial interactions between the adjacent PDI units in its structure lead to excimer formation. These excimer states trap the singlet excitons preventing the formation of the 1[TT] state, thus inhibiting iSEF.
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Affiliation(s)
- Angelar K Muthike
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Benedetta Carlotti
- Department of Chemistry Biology and Biotechnology, University of Perugia, via Elce di Sotto n.8, 06123 Perugia, Italy
| | - Ifeanyi K Madu
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Hanjie Jiang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Hyungjun Kim
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.,Department of Chemistry, Incheon National University, Incheon 22012, Republic of Korea
| | - Qinghe Wu
- Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Luping Yu
- Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Theodore Goodson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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37
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Yang X, Gitter SR, Roessler AG, Zimmerman PM, Boydston AJ. An Ion‐Pairing Approach to Stereoselective Metal‐Free Ring‐Opening Metathesis Polymerization. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016393] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Xuejin Yang
- Department of Chemistry University of Wisconsin-Madison Madison WI 53706 USA
| | - Sean R. Gitter
- Department of Chemistry University of Wisconsin-Madison Madison WI 53706 USA
| | - Allison G. Roessler
- Department of Chemistry University of Michigan Ann Arbor MI 48109 USA
- Department of Chemistry Oglethorpe University Atlanta GA 30319 USA
| | - Paul M. Zimmerman
- Department of Chemistry University of Michigan Ann Arbor MI 48109 USA
| | - Andrew J. Boydston
- Department of Chemistry University of Wisconsin-Madison Madison WI 53706 USA
- Department of Chemical and Biological Engineering Department of Materials Science and Engineering University of Wisconsin-Madison Madison WI 53706 USA
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38
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Aldaz CR, Wiley TE, Miller NA, Abeyrathna N, Liao Y, Zimmerman PM, Sension RJ. Experimental and Theoretical Characterization of Ultrafast Water-Soluble Photochromic Photoacids. J Phys Chem B 2021; 125:4120-4131. [PMID: 33872018 DOI: 10.1021/acs.jpcb.1c00644] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
UV-visible transient absorption spectroscopy and quantum mechanical simulations are combined to elucidate the photochemical mechanism of two metastable merocyanine/spiropyran photoacids, 2-[(E)-2-(2-hydroxyphenyl)ethenyl]-3,3-dimethyl-1-(3-sulfopropyl)-3H-indol-1-ium (phenylhydroxy-MCH) and 2-[(E)-2-(1H-indazol-7-yl)ethenyl]-3-(3-sulfopropyl)-1,3-benzothiazol-3-ium (indazole-MCH). Transient absorption spectra demonstrate that trans-acid isomerization to the cis form results in deprotonation on a picosecond time scale. Ring closure to form spiropyran follows promptly from the appropriate conformation or follows at longer time delays (≫3.5 ns) following a barrier crossing for single-bond isomerization to the appropriate conformation. Consistent with the results of Berton et al. [ Chem. Sci. 2020, 11, 8457-8468] , we find that cis-phenylhydroxy-MCH is a stronger acid than trans-phenylhydroxy-MCH. The decrease in pKa upon isomerization is further investigated to benchmark quantum chemical methods for their accuracy. Calculations were performed with nine levels of theory including continuum solvent models and explicit water. The calculations are not sufficient to describe the ΔpKa following isomerization of these photoacids, and more work is necessary to properly evaluate the physical basis for the acidity of the cis photoacids.
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Affiliation(s)
- Cody R Aldaz
- Department of Chemistry, University of Michigan, 930 North University Avenue Ann Arbor, Michigan 48109-1055, United States
| | - Theodore E Wiley
- Department of Chemistry, University of Michigan, 930 North University Avenue Ann Arbor, Michigan 48109-1055, United States
| | - Nicholas A Miller
- Department of Chemistry, University of Michigan, 930 North University Avenue Ann Arbor, Michigan 48109-1055, United States
| | - Nawodi Abeyrathna
- Department of Chemistry, Florida Institute of Technology Melbourne, Florida 32901-8636, United States
| | - Yi Liao
- Department of Chemistry, Florida Institute of Technology Melbourne, Florida 32901-8636, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 North University Avenue Ann Arbor, Michigan 48109-1055, United States
| | - Roseanne J Sension
- Department of Chemistry, University of Michigan, 930 North University Avenue Ann Arbor, Michigan 48109-1055, United States
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39
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Malakar T, Hanson CS, Devery JJ, Zimmerman PM. Combined Theoretical and Experimental Investigation of Lewis Acid-Carbonyl Interactions for Metathesis. ACS Catal 2021; 11:4381-4394. [PMID: 34017648 DOI: 10.1021/acscatal.0c05277] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The coordination of a carbonyl to a Lewis acid represents the first step in a wide range of catalytic transformations. In many reactions it is necessary for the Lewis acid to discriminate between starting material and product, and as a result, how these structures behave in solution must be characterized. Herein, we report the application of computational modeling to calculate properties of the solution interactions of acetone and benzaldehyde with FeCl3. Using these chemical models, we can predict spectral features in the carbonyl region of infrared (IR) spectroscopy. These simulated spectra are then directly compared to experimental spectra generated via titration-IR. We observe good agreement between theory and experiment, in that, between 0 and 1 equiv carbonyl with respect to FeCl3, a pairwise interaction dominates the spectra. When >1 equiv carbonyl is present, our theoretical model predicts two possible structures composed of 4:1 carbonyl to FeCl3, for acetone as well as benzaldehyde. When these predicted spectra are compared with titration-IR data, both structures contribute to the observed solution interactions. These findings suggest that the resting state of FeCl3-catalyzed carbonyl-based reactions employing simple substrates starts as a Lewis pair, but this structure is gradually consumed and becomes a highly ligated, catalytically less active Fe-centered complex as the reaction proceeds. An analytical model is proposed to quantify catalyst inhibition due to equilibrium between 1:1 and 4:1 carbonyl:Fe complexes.
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Affiliation(s)
- Tanmay Malakar
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Carly S. Hanson
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 West Sheridan Road, Chicago, Illinois 60660, United States
| | - James J. Devery
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 West Sheridan Road, Chicago, Illinois 60660, United States
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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40
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Affiliation(s)
- Alan E. Rask
- Department of Chemistry, University of Michigan, 930N. University Avenue, Ann Arbor 48109, Michigan, United States
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, 930N. University Avenue, Ann Arbor 48109, Michigan, United States
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41
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Malakar T, Zimmerman PM. Brønsted-Acid-Catalyzed Intramolecular Carbonyl-Olefin Reactions: Interrupted Metathesis vs Carbonyl-Ene Reaction. J Org Chem 2021; 86:3008-3016. [PMID: 33475347 DOI: 10.1021/acs.joc.0c03021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Lewis acid catalysts have been shown to promote carbonyl-olefin metathesis through a critical four-membered-ring oxetane intermediate. Recently, Brønsted-acid catalysis of related substrates was similarly proposed to result in a transient oxetane, which fragments within a single elementary step via a postulated oxygen-atom transfer mechanism. Herein, careful quantum chemical investigations show that Brønsted acid (triflic acid, TfOH) instead invokes a mechanistic switch to a carbonyl-ene reaction, and oxygen-atom transfer is uncompetitive. TfOH's conjugate base is also found to rearrange H atoms and allow isomerization of the carbocations that appear after the carbonyl-ene reaction. The mechanism explains available experimental information, including the skipped diene species that appear transiently before product formation. The present study clarifies the mechanism for activation of intramolecular carbonyl-olefin substrates by Brønsted acids and provides important insights that will help develop this exciting class of catalysts.
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Affiliation(s)
- Tanmay Malakar
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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42
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Affiliation(s)
- Duy-Khoi Dang
- University of Michigan, 930 N University Ave., Ann Arbor, Michigan 48109, USA
| | - Paul M. Zimmerman
- University of Michigan, 930 N University Ave., Ann Arbor, Michigan 48109, USA
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43
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Carreras A, Jiang H, Pokhilko P, Krylov AI, Zimmerman PM, Casanova D. Calculation of spin–orbit couplings using RASCI spinless one-particle density matrices: Theory and applications. J Chem Phys 2020; 153:214107. [DOI: 10.1063/5.0029146] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Abel Carreras
- Donostia International Physics Center (DIPC), Manuel de Lardizabal Pasalekua 4, 20018 Donostia, Euskadi, Spain
| | - Hanjie Jiang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Pavel Pokhilko
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Anna I. Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - David Casanova
- Donostia International Physics Center (DIPC), Manuel de Lardizabal Pasalekua 4, 20018 Donostia, Euskadi, Spain
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44
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Aldaz CR, Martinez TJ, Zimmerman PM. The Mechanics of the Bicycle Pedal Photoisomerization in Crystalline cis,cis-1,4-Diphenyl-1,3-butadiene. J Phys Chem A 2020; 124:8897-8906. [PMID: 33064471 DOI: 10.1021/acs.jpca.0c05803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Direct irradiation of crystalline cis,cis-1,4-diphenyl-1,3-butadiene (cc-DPB) forms trans,trans-1,4-diphenyl-1,3,-butadiene via a concerted two-bond isomerization called the bicycle pedal (BP) mechanism. However, little is known about photoisomerization pathways in the solid state and there has been much debate surrounding the interpretation of volume-conserving isomerization mechanisms. The bicycle pedal photoisomerization is investigated using the quantum mechanics/molecular mechanics complete active space self-consistent field/Amber force-field method. Important details about how the steric environment influences isomerization mechanisms are revealed including how the one-bond flip and hula-twist mechanisms are suppressed by the crystal cavity, the nature of the seam space in steric environments, and the features of the bicycle pedal mechanism. Specifically, in the bicycle pedal, the phenyl rings of cc-DPB are locked in place and the intermolecular packing allows a passageway for rotation of the central diene in a volume-conserving manner. In contrast, the bicycle pedal rotation in the gas phase is not a stable pathway, so single-bond rotation mechanisms become operative instead. Furthermore, the crystal BP mechanism is an activated process that occurs completely on the excited state; the photoproduct can decay to the ground state through radiative and non-radiative pathways. The present models, however, do not capture the quantitative activation barriers, and more work is needed to better model reactions in crystals. Last, the reaction barriers of the different crystalline conformations within the unit cell of cc-DPB are compared to investigate the possibility for conformation-dependent isomerization. Although some difference in reaction barriers is observed, the difference is most likely not responsible for the experimentally observed periods of fast and slow conversion.
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Affiliation(s)
- Cody R Aldaz
- Department of Chemistry, University of Michigan, 930 N University Ave., Ann Arbor, Michigan 48109-1055, United States
| | - Todd J Martinez
- Department of Chemistry and the PULSE Institute, Stanford University, Stanford, California 94305, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 N University Ave., Ann Arbor, Michigan 48109-1055, United States
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45
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Jiang H, Zimmerman PM. Charge transfer via spin flip configuration interaction: Benchmarks and application to singlet fission. J Chem Phys 2020; 153:064109. [DOI: 10.1063/5.0018267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Hanjie Jiang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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46
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Carlotti B, Madu IK, Kim H, Cai Z, Jiang H, Muthike AK, Yu L, Zimmerman PM, Goodson T. Activating intramolecular singlet exciton fission by altering π-bridge flexibility in perylene diimide trimers for organic solar cells. Chem Sci 2020; 11:8757-8770. [PMID: 34123128 PMCID: PMC8163386 DOI: 10.1039/d0sc03271a] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/06/2020] [Indexed: 01/01/2023] Open
Abstract
In this study, two analogous perylene diimide (PDI) trimers, whose structures show rotatable single bond π-bridge connection (twisted) vs. rigid/fused π-bridge connection (planar), were synthesized and investigated. We show via time resolved spectroscopic measurements how the π-bridge connections in A-π-D-π-A-π-D-π-A multichromophoric PDI systems strongly affect the triplet yield and triplet formation rate. In the planar compound, with stronger intramolecular charge transfer (ICT) character, triplet formation occurs via conventional intersystem crossing. However, clear evidence of efficient and fast intramolecular singlet exciton fission (iSEF) is observed in the twisted trimer compound with weaker ICT character. Multiexciton triplet generation and separation occur in the twisted (flexible-bridged) PDI trimer, where weak coupling among the units is observed as a result of the degenerate double triplet and quintet states, obtained by quantum chemical calculations. The high triplet yield and fast iSEF observed in the twisted compound are due not only to enthalpic viability but also to the significant entropic gain allowed by its trimeric structure. Our results represent a significant step forward in structure-property understanding, and may direct the design of new efficient iSEF materials.
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Affiliation(s)
- Benedetta Carlotti
- Department of Chemistry, University of Michigan Ann Arbor MI 48109 USA
- Department of Chemistry Biology and Biotechnology, University of Perugia via Elce di Sotto n.8 06123 Perugia Italy
| | - Ifeanyi K Madu
- Department of Chemistry, University of Michigan Ann Arbor MI 48109 USA
| | - Hyungjun Kim
- Department of Chemistry, University of Michigan Ann Arbor MI 48109 USA
- Department of Chemistry, Incheon National University Incheon 22012 Republic of Korea
| | - Zhengxu Cai
- Department of Chemistry, The James Franck Institute, The University of Chicago 929 East 57th Street Chicago IL 60637 USA
| | - Hanjie Jiang
- Department of Chemistry, University of Michigan Ann Arbor MI 48109 USA
| | - Angelar K Muthike
- Department of Chemistry, University of Michigan Ann Arbor MI 48109 USA
| | - Luping Yu
- Department of Chemistry, The James Franck Institute, The University of Chicago 929 East 57th Street Chicago IL 60637 USA
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan Ann Arbor MI 48109 USA
| | - Theodore Goodson
- Department of Chemistry, University of Michigan Ann Arbor MI 48109 USA
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47
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Lipinski BM, Walker KL, Clayman NE, Morris LS, Jugovic TME, Roessler AG, Getzler YDYL, MacMillan SN, Zare RN, Zimmerman PM, Waymouth RM, Coates GW. Mechanistic Study of Isotactic Poly(propylene oxide) Synthesis using a Tethered Bimetallic Chromium Salen Catalyst. ACS Catal 2020; 10:8960-8967. [PMID: 34367720 DOI: 10.1021/acscatal.0c02135] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Initial catalyst dormancy has been mitigated for the enantioselective polymerization of propylene oxide using a tethered bimetallic chromium(III) salen complex. A detailed mechanistic study provided insight into the species responsible for this induction period and guided efforts to remove them. High-resolution electrospray ionization-mass spectrometry and density functional theory computations revealed that a μ-hydroxide and a bridged 1,2-hydroxypropanolate complex are present during the induction period. Kinetic studies and additional computation indicated that the μ-hydroxide complex is a short-lived catalyst arrest state, where hydroxide dissociation from one metal allows for epoxide enchainment to form the 1,2-hydroxypropanolate arrest state. While investigating anion dependence on the induction period, it became apparent that catalyst activation was the main contributor for dormancy. Using a 1,2-diol or water as chain transfer agents (CTAs) led to longer induction periods as a result of increased 1,2-hydroxyalkanolate complex formation. With a minor catalyst modification, rigorous drying conditions, and avoiding 1,2-diols as CTAs, the induction period was essentially removed.
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Affiliation(s)
- Bryce M. Lipinski
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United States
| | - Katherine L. Walker
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Naomi E. Clayman
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Lilliana S. Morris
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United States
| | - Timothy M. E. Jugovic
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1382, United States
| | - Allison G. Roessler
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1382, United States
| | - Yutan D. Y. L. Getzler
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United States
| | - Samantha N. MacMillan
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United States
| | - Richard N. Zare
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1382, United States
| | - Robert M. Waymouth
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Geoffrey W. Coates
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, United States
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Vitek AK, Jugovic TME, Zimmerman PM. Revealing the Strong Relationships between Ligand Conformers and Activation Barriers: A Case Study of Bisphosphine Reductive Elimination. ACS Catal 2020. [DOI: 10.1021/acscatal.0c00618] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew K. Vitek
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Timothy M. E. Jugovic
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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Abstract
Large mass-independent fractionation signatures in Hg have been observed in the laboratory and the environment, prompting deep questions about the chemical reasons behind these signatures. Since the relative lack of mechanistic information about Hg chemistry in the environment has precluded explanations of these isotope effects, the present study uses high-level electronic structure methods to evaluate the possible photochemical mechanisms of mass-independent isotope effects (MIEs) in HgX2 and CH3HgX (X = Cl, Br, I, and SCH3). The results show that spin-orbit coupling wipes out the potential of MIEs for Hg bound to Br or I, but that complexes involving lighter elements, HgX2 and CH3HgX (X = Cl and SCH3), have relatively small spin-orbit couplings upon photolysis. This unexpected finding shows that magnetic isotope fractionation due to hyperfine coupling is possible, depending on the identity of the Hg complex. By examination of the photolysis potential energy profiles, this study shows that HgX2 complexes can have a positive or a negative MIE (depending on reaction conditions), while CH3HgX complexes exclusively result in a positive MIE. These findings agree with MIE recorded in natural samples, demonstrating a plausible mechanism for the surprising mass-independent fractionation of Hg in the environment.
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Affiliation(s)
- Laura C Motta
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Alan D Chien
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Alan E Rask
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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50
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Wang S, Arguelles AJ, Tay JH, Hotta M, Zimmerman PM, Nagorny P. Experimental and Computational Studies on Regiodivergent Chiral Phosphoric Acid Catalyzed Cycloisomerization of Mupirocin Methyl Ester. Chemistry 2020; 26:4583-4591. [PMID: 31905253 PMCID: PMC7261366 DOI: 10.1002/chem.201905222] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/01/2020] [Indexed: 12/17/2022]
Abstract
This article presents a new strategy for achieving regiocontrol over the endo versus exo modes of cycloisomerizations of epoxide-containing alcohols, which leads to the formation of five- or six-membered cyclic ethers. Unlike traditional methods relying on achiral reagents or enzymes, this approach utilizes chiral phosphoric acids to catalyze the regiodivergent selective formations of either tetrahydrofuran- or tetrahydropyran-containing products. By using methyl ester of epoxide-containing antibiotic mupirocin as the substrate, it is demonstrated that catalytic chiral phosphoric acids (R)-TCYP and (S)-TIPSY could be used to achieve the selective formation of either the six-membered endo product (95:5 r.r.) or the five-membered exo product (77:23 r.r.), correspondingly. This cyclization was found to be unselective under the standard conditions involving various achiral acids, bases, or buffers. The subsequent mechanistic studies using state-of-the-art quantum chemical solutions provided the description of the potential energy surface, which is fully consistent with the experimental observations. Based on these results, highly detailed reaction paths are obtained and a concerted and highly synchronous mechanism is proposed for the formation of both exo and endo products.
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Affiliation(s)
- Sibin Wang
- Chemistry Department, University of Michigan, 930N. University Ave., Ann Arbor, MI, 48109, USA
| | - Alonso J Arguelles
- Eli Lilly and Company, 1500 South Harding Street, Indiana, IN, 46221, USA
| | - Jia-Hui Tay
- Corteva Agriscience, 9330 Zionsville Rd., Indianapolis, IN, 46268, USA
| | - Miyuki Hotta
- Chemistry Department, University of Michigan, 930N. University Ave., Ann Arbor, MI, 48109, USA
| | - Paul M Zimmerman
- Chemistry Department, University of Michigan, 930N. University Ave., Ann Arbor, MI, 48109, USA
| | - Pavel Nagorny
- Chemistry Department, University of Michigan, 930N. University Ave., Ann Arbor, MI, 48109, USA
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