1
|
Tang J, Zhang S, Zhou BW, Wang W, Zhao L. Hyperconjugative Aromaticity-Based Circularly Polarized Luminescence Enhancement in Polyaurated Heterocycles. J Am Chem Soc 2023; 145:23442-23451. [PMID: 37870916 DOI: 10.1021/jacs.3c04953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2023]
Abstract
Hyperconjugative aromaticity (HA) frequently appears in metalla-aromatics, but its effect on photophysical properties remains unexplored to date. Herein, we reveal two different HA scenarios in nearly isostructural triaurated indolium and benzofuranylium compounds. The biased HAs show a discernible effect on the spatial arrangement of metal atoms and thus tailor metal parentage in frontier orbitals and the HOMO-LUMO energy gap. Theoretical calculations and structural analyses demonstrate that HA not only influences the degree of electron delocalization over the trimetalated aromatic rings but also affects π-coordination of Au(I) and intercluster aurophilic interaction. Consequently, the triaurated benzofuranylium complex shows better photoluminescence performance (quantum yield up to 49.7%) over the indolium analogue. Furthermore, four pairs of axially chiral bibenzofuran-centered trinuclear and hexanuclear gold clusters were purposefully synthesized to correlate their HA-involved structures with the chiroptical response. The triaurated benzofuranylium complexes exhibit strong circular dichroism (CD) response in solution but CPL silence even in solid film. In contrast, the hexa-aurated homologues display strong CD and intense CPL signals in both aggregated state and solid film (luminescence anisotropy factor glum up to 10-3). Their amplified chiroptical response is finally ascribed to the dominant intermolecular exciton couplings of large assemblies formed through the HA-tailored aggregation of hexanuclear compounds.
Collapse
Affiliation(s)
- Jian Tang
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
- Sinopec (Beijing) Research Institute of Chemical Industry, Beijing 100013, China
| | - Siqi Zhang
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Bo-Wei Zhou
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Wan Wang
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Liang Zhao
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
| |
Collapse
|
2
|
Kukier GA, Turlik A, Xue XS, Houk KN. Violations. How Nature Circumvents the Woodward-Hoffmann Rules and Promotes the Forbidden Conrotatory 4 n + 2 Electron Electrocyclization of Prinzbach's Vinylogous Sesquifulvalene. J Am Chem Soc 2021; 143:21694-21704. [PMID: 34911295 DOI: 10.1021/jacs.1c11058] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Woodward and Hoffmann, in their treatise on orbital symmetry in 1969, stated "Violations. There are none!" Prinzbach reported in 1978 that the electrocyclization of vinylogous sesquifulvalene occurs exclusively through the Woodward-Hoffmann orbital-symmetry-forbidden 14π-electron conrotatory pathway, despite the availability of a variety of orbital-symmetry-allowed processes. Prinzbach later demonstrated that an 18π-electron homologue exhibits the same forbidden behavior. And yet, the analogous vinylogous pentafulvalene and heptafulvalene both follow the orbital symmetry rules, each proceeding through its allowed conrotatory 12π and 16π process, respectively. We report the investigation of these reactions with ωB97X-D DFT. The physical origins of the flagrant Prinzbach violations of the Woodward-Hoffmann orbital symmetry selection rules have now been elucidated by these calculations in conjunction with extensive analyses and comparisons to electrocyclizations that obey the Woodward-Hoffmann rules. This remarkable reversal of the Rules (the 14π-electron-forbidden process is found to be 11 kcal/mol more energetically facile than the allowed process) occurs due to the high degree of polarization of this hydrocarbon, such that conrotatory electrocyclization of vinylogous sesquifulvalene behaves like a cyclopentadienide combining with a tropylium. These results are compared to other forbidden pericyclic processes driven by steric constraints and strain release or by diradical character of the reactants that facilitates the formation of diradical transition states for symmetry-forbidden reactions. We predict how strong donor-acceptor substitution can modify nodal properties to level the difference between allowed and forbidden electrocyclic reaction barriers, and we provide computational predictions of two such cases.
Collapse
Affiliation(s)
- Garrett A Kukier
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Aneta Turlik
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Xiao-Song Xue
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| |
Collapse
|
3
|
Cai Y, Hua Y, Lu Z, Lan Q, Lin Z, Fei J, Chen Z, Zhang H, Xia H. Electrophilic aromatic substitution reactions of compounds with Craig-Möbius aromaticity. Proc Natl Acad Sci U S A 2021; 118:e2102310118. [PMID: 34544859 PMCID: PMC8488665 DOI: 10.1073/pnas.2102310118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2021] [Indexed: 11/18/2022] Open
Abstract
Electrophilic aromatic substitution (EAS) reactions are widely regarded as characteristic reactions of aromatic species, but no comparable reaction has been reported for molecules with Craig-Möbius aromaticity. Here, we demonstrate successful EAS reactions of Craig-Möbius aromatics, osmapentalenes, and fused osmapentalenes. The highly reactive nature of osmapentalene makes it susceptible to electrophilic attack by halogens, thus osmapentalene, osmafuran-fused osmapentalene, and osmabenzene-fused osmapentalene can undergo typical EAS reactions. In addition, the selective formation of a series of halogen substituted metalla-aromatics via EAS reactions has revealed an unprecedented approach to otherwise elusive compounds such as the unsaturated cyclic chlorirenium ions. Density functional theory calculations were conducted to study the electronic effect on the regioselectivity of the EAS reactions.
Collapse
Affiliation(s)
- Yuanting Cai
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China 361005
| | - Yuhui Hua
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China 361005
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, China 518005
| | - Zhengyu Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China 361005
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, China 518005
| | - Qing Lan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China 361005
| | - Zuzhang Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China 361005
| | - Jiawei Fei
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China 361005
| | - Zhixin Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China 361005
| | - Hong Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China 361005;
| | - Haiping Xia
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China 361005;
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, China 518005
| |
Collapse
|
4
|
Cheung LF, Kocheril GS, Czekner J, Wang LS. Observation of Möbius Aromatic Planar Metallaborocycles. J Am Chem Soc 2020; 142:3356-3360. [PMID: 32039591 DOI: 10.1021/jacs.9b13417] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Ling Fung Cheung
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - G. Stephen Kocheril
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Joseph Czekner
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| |
Collapse
|
5
|
Xiao K, Zhao Y, Zhu J, Zhao L. Hyperconjugative aromaticity and protodeauration reactivity of polyaurated indoliums. Nat Commun 2019; 10:5639. [PMID: 31822673 PMCID: PMC6904676 DOI: 10.1038/s41467-019-13663-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 11/14/2019] [Indexed: 12/16/2022] Open
Abstract
Aromaticity generally describes a cyclic structure composed of sp2-hybridized carbon or hetero atoms with remarkable stability and unique reactivity. The doping of even one sp3-hybridized atom often damages the aromaticity due to the interrupted electron conjugation. Here we demonstrate the occurrence of an extended hyperconjugative aromaticity (EHA) in a metalated indole ring which contains two gem-diaurated tetrahedral carbon atoms. The EHA-involved penta-aurated indolium shows extended electron conjugation because of dual hyperconjugation. Furthermore, the EHA-induced low electron density on the indolyl nitrogen atom enables a facile protodeauration reaction for the labile Au-N bond. In contrast, the degraded tetra-aurated indolium with a single gem-dimetalated carbon atom exhibits poor bond averaging and inertness in the protodeauration reaction. The aromaticity difference in such two polyaurated indoliums is discussed in the geometrical and electronic perspectives. This work highlights the significant effect of metalation on the aromaticity of polymetalated species. Hyperconjugative aromaticity combines the concepts of hyperconjugation and aromaticity and explains cyclopentadiene stability. Here, the authors demonstrate extended hyperconjugative aromaticity in a metallated indole ring, which shows extended electron conjugation due to the dual hyperconjugation.
Collapse
Affiliation(s)
- Kui Xiao
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, 100084, Beijing, China
| | - Yu Zhao
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China.
| | - Liang Zhao
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, 100084, Beijing, China.
| |
Collapse
|
6
|
Yasui K, Kamitani M, Tobisu M. N‐Heterocyclic Carbene Catalyzed Concerted Nucleophilic Aromatic Substitution of Aryl Fluorides Bearing α,β‐Unsaturated Amides. Angew Chem Int Ed Engl 2019; 58:14157-14161. [DOI: 10.1002/anie.201907837] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/23/2019] [Indexed: 02/05/2023]
Affiliation(s)
- Kosuke Yasui
- Department of Applied Chemistry Graduate School of Engineering Osaka University Suita Osaka 565-0871 Japan
| | - Miharu Kamitani
- Department of Applied Chemistry Graduate School of Engineering Osaka University Suita Osaka 565-0871 Japan
| | - Mamoru Tobisu
- Department of Applied Chemistry Graduate School of Engineering Osaka University Suita Osaka 565-0871 Japan
| |
Collapse
|
7
|
Yasui K, Kamitani M, Tobisu M. N‐Heterocyclic Carbene Catalyzed Concerted Nucleophilic Aromatic Substitution of Aryl Fluorides Bearing α,β‐Unsaturated Amides. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201907837] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Kosuke Yasui
- Department of Applied Chemistry Graduate School of Engineering Osaka University Suita Osaka 565-0871 Japan
| | - Miharu Kamitani
- Department of Applied Chemistry Graduate School of Engineering Osaka University Suita Osaka 565-0871 Japan
| | - Mamoru Tobisu
- Department of Applied Chemistry Graduate School of Engineering Osaka University Suita Osaka 565-0871 Japan
| |
Collapse
|