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Silva AJFWHDS, Rodrigues GP, Ventura E, do Monte SA. Photodissociation and formation of an ion-pair in CH 2 FCl (HCFC-31). J Comput Chem 2024; 45:476-486. [PMID: 37950575 DOI: 10.1002/jcc.27257] [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: 08/13/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 11/12/2023]
Abstract
Although CH2 FCl (HCFC-31) recently became of great atmospheric importance, studies concerning its excited states are almost nonexistent. Several excited singlet states were studied (valence nσ* and Rydberg n3s, n3p, σ3s, and σ3p) through highly correlated multireference configuration interaction with singles and doubles, including extensivity correction. Comparison with the states of CH3 Cl indicates a strong influence of the F atom. Potential energy curves suggest formation of an electrostatically bound complex that relaxes to a hydrogen-bonded contact ion-pair (HBCIP) which can decay yielding CH2 F + Cl or to the ground state minimum of CH2 FCl. The HBCIP has a dipole moment of 9.57 D, a CI wavefunction described as 0.65ionic + 0.20biradical and it is strongly bonded by 4.72 eV. Its H bond has characteristics of moderate and strong H bonds. The simulated absorption spectrum confirms the nσ* assignment for the first and suggests the n3s + n3pσ assignment for the second band.
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Affiliation(s)
| | | | - Elizete Ventura
- Chemistry Department, Universidade Federal da Paraíba, Joao Pessoa, Brazil
| | - Silmar A do Monte
- Chemistry Department, Universidade Federal da Paraíba, Joao Pessoa, Brazil
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2
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Toldo JM, do Casal MT, Ventura E, do Monte SA, Barbatti M. Surface hopping modeling of charge and energy transfer in active environments. Phys Chem Chem Phys 2023; 25:8293-8316. [PMID: 36916738 PMCID: PMC10034598 DOI: 10.1039/d3cp00247k] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
An active environment is any atomic or molecular system changing a chromophore's nonadiabatic dynamics compared to the isolated molecule. The action of the environment on the chromophore occurs by changing the potential energy landscape and triggering new energy and charge flows unavailable in the vacuum. Surface hopping is a mixed quantum-classical approach whose extreme flexibility has made it the primary platform for implementing novel methodologies to investigate the nonadiabatic dynamics of a chromophore in active environments. This Perspective paper surveys the latest developments in the field, focusing on charge and energy transfer processes.
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Affiliation(s)
| | | | - Elizete Ventura
- Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Brazil.
| | - Silmar A do Monte
- Departamento de Química, CCEN, Universidade Federal da Paraíba, 58059-900, João Pessoa, Brazil.
| | - Mario Barbatti
- Aix-Marseille University, CNRS, ICR, Marseille, France.
- Institut Universitaire de France, 75231, Paris, France
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3
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Bezerra MG, Leitão EFV, de Andrade RB, Ventura E, do Monte SA. Photochemistry of Monohydrated Chloromethane: Formation of Free and Hydrated Cl - and CH 3+ Ions from a Solvent-Shared Semi-Ion-Pair. J Phys Chem A 2021; 125:8603-8614. [PMID: 34582197 DOI: 10.1021/acs.jpca.1c05704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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
The effect of water molecule on the excited states of CH3Cl(H2O), as compared to those of the isolated chloromethane, has been studied at the multireference configuration interaction with singles and doubles (MR-CISD), including extensivity corrections. Eight new Rydberg states are due to the water molecule but the common states of both systems are not severely altered. Potential energy curves of 23 singlet states along the C-Cl coordinate have also been computed at the MR-CISD level. The dissociation energy of the C-Cl bond decreases from ∼0.4 to 0.5 eV due to the water molecule. As for CH3Cl (de Medeiros, V. C., J. Am. Chem. Soc. 2016, 138, 272-280), a stable ion-pair has also been characterized. However, for CH3Cl(H2O), this ion-pair is better described as a solvent-shared semi-ion-pair, CH3+δ(H2O)Cl-δ. This species is connected with three ionic dissociation channels, with two being due to the water molecule. The presence of these new ionic channels, particularly the lowest energy one, [H3C-O]+ + Cl-, raises a very important question of atmospheric relevance: can the interaction of chloroalkanes with water decrease its deleterious effect on the ozone layer? Several potentially new competing dissociation channels are also studied. The latter results can help to set up the most important states to be included in nonadiabatic dynamic calculations to study how the yields of the ionic channels change due to the water molecule.
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Affiliation(s)
- Mariana G Bezerra
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa, PB 58-059-900, Brazil
| | - Ezequiel F V Leitão
- Unidade Acadêmica de Ciências Exatas e da Natureza, Universidade Federal de Campina Grande, Cajazeiras, PB 58900-000, Brazil
| | - Railton B de Andrade
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa, PB 58-059-900, Brazil
| | - Elizete Ventura
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa, PB 58-059-900, Brazil
| | - Silmar A do Monte
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa, PB 58-059-900, Brazil
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4
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Araújo JR, de Andrade RB, Batista HJ, Ventura E, do Monte SA. Can a gas phase contact ion pair containing a hydrocarbon carbocation be formed in the ground state? RSC Adv 2021; 11:4221-4230. [PMID: 35424376 PMCID: PMC8694316 DOI: 10.1039/d0ra10523f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 12/14/2020] [Accepted: 01/11/2021] [Indexed: 11/21/2022] Open
Abstract
So far, no conclusive evidence of a ground-state contact ion-pair containing a hydrocarbon carbocation has been given in the gas phase.
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Affiliation(s)
- José R. Araújo
- Departamento de Química
- CCEN
- Universidade Federal da Paraíba
- João Pessoa
- Brazil
| | | | - Hélcio J. Batista
- Departamento de Química
- Universidade Federal Rural de Pernambuco
- Recife
- Brazil
| | - Elizete Ventura
- Departamento de Química
- CCEN
- Universidade Federal da Paraíba
- João Pessoa
- Brazil
| | - Silmar A. do Monte
- Departamento de Química
- CCEN
- Universidade Federal da Paraíba
- João Pessoa
- Brazil
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Lischka H, Shepard R, Müller T, Szalay PG, Pitzer RM, Aquino AJA, Araújo do Nascimento MM, Barbatti M, Belcher LT, Blaudeau JP, Borges I, Brozell SR, Carter EA, Das A, Gidofalvi G, González L, Hase WL, Kedziora G, Kertesz M, Kossoski F, Machado FBC, Matsika S, do Monte SA, Nachtigallová D, Nieman R, Oppel M, Parish CA, Plasser F, Spada RFK, Stahlberg EA, Ventura E, Yarkony DR, Zhang Z. The generality of the GUGA MRCI approach in COLUMBUS for treating complex quantum chemistry. J Chem Phys 2020; 152:134110. [PMID: 32268762 DOI: 10.1063/1.5144267] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The core part of the program system COLUMBUS allows highly efficient calculations using variational multireference (MR) methods in the framework of configuration interaction with single and double excitations (MR-CISD) and averaged quadratic coupled-cluster calculations (MR-AQCC), based on uncontracted sets of configurations and the graphical unitary group approach (GUGA). The availability of analytic MR-CISD and MR-AQCC energy gradients and analytic nonadiabatic couplings for MR-CISD enables exciting applications including, e.g., investigations of π-conjugated biradicaloid compounds, calculations of multitudes of excited states, development of diabatization procedures, and furnishing the electronic structure information for on-the-fly surface nonadiabatic dynamics. With fully variational uncontracted spin-orbit MRCI, COLUMBUS provides a unique possibility of performing high-level calculations on compounds containing heavy atoms up to lanthanides and actinides. Crucial for carrying out all of these calculations effectively is the availability of an efficient parallel code for the CI step. Configuration spaces of several billion in size now can be treated quite routinely on standard parallel computer clusters. Emerging developments in COLUMBUS, including the all configuration mean energy multiconfiguration self-consistent field method and the graphically contracted function method, promise to allow practically unlimited configuration space dimensions. Spin density based on the GUGA approach, analytic spin-orbit energy gradients, possibilities for local electron correlation MR calculations, development of general interfaces for nonadiabatic dynamics, and MRCI linear vibronic coupling models conclude this overview.
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Affiliation(s)
- Hans Lischka
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
| | - Ron Shepard
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Thomas Müller
- Institute for Advanced Simulation, Jülich Supercomputing Centre, Forschungszentrum Jülich, Jülich 52428, Germany
| | - Péter G Szalay
- ELTE Eötvös Loránd University, Institute of Chemistry, Budapest, Hungary
| | - Russell M Pitzer
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Adelia J A Aquino
- School of Pharmaceutical Sciences and Technology, Tianjin University, Tianjin 300072, People's Republic of China
| | | | | | - Lachlan T Belcher
- Laser and Optics Research Center, Department of Physics, US Air Force Academy, Colorado 80840, USA
| | | | - Itamar Borges
- Departamento de Química, Instituto Militar de Engenharia, Rio de Janeiro, RJ 22290-270, Brazil
| | - Scott R Brozell
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Emily A Carter
- Office of the Chancellor and Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Box 951405, Los Angeles, California 90095-1405, USA
| | - Anita Das
- Indian Institute of Engineering Science and Technology, Shibpur, Howrah, India
| | - Gergely Gidofalvi
- Department of Chemistry and Biochemistry, Gonzaga University, Spokane, Washington 99258, USA
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria
| | - William L Hase
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
| | - Gary Kedziora
- Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA
| | - Miklos Kertesz
- Department of Chemistry, Georgetown University, 37th and O Streets, NW, Washington, DC 20057-1227, USA
| | | | - Francisco B C Machado
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos 12228-900, São Paulo, Brazil
| | - Spiridoula Matsika
- Department of Chemistry, Temple University, 1901 N. 13th St., Philadelphia, Pennsylvania 19122, USA
| | | | - Dana Nachtigallová
- Institute of Organic Chemistry and Biochemistry v.v.i., The Czech Academy of Sciences, Flemingovo nám. 2, 160610 Prague 6, Czech Republic
| | - Reed Nieman
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
| | - Markus Oppel
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria
| | - Carol A Parish
- Department of Chemistry, Gottwald Center for the Sciences, University of Richmond, Richmond, Virginia 23173, USA
| | - Felix Plasser
- Department of Chemistry, Loughborough University, Loughborough LE11 3TU, United Kingdom
| | - Rene F K Spada
- Departamento de Física, Instituto Tecnológico de Aeronáutica, São José dos Campos 12228-900, São Paulo, Brazil
| | - Eric A Stahlberg
- Biomedical Informatics and Data Science, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Elizete Ventura
- Universidade Federal da Paraíba, 58059-900 João Pessoa, PB, Brazil
| | - David R Yarkony
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, USA
| | - Zhiyong Zhang
- Stanford Research Computing Center, Stanford University, 255 Panama Street, Stanford, California 94305, USA
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de Medeiros VC, de Andrade RB, P. Rodrigues G, Bauerfeldt GF, Ventura E, Barbatti M, do Monte SA. Photochemistry of CF3Cl: Quenching of Charged Fragments Is Caused by Nonadiabatic Effects. J Chem Theory Comput 2018; 14:4844-4855. [DOI: 10.1021/acs.jctc.8b00457] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [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)
- Vanessa C. de Medeiros
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa, Paraíba 58.059-900, Brazil
| | - Railton B. de Andrade
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa, Paraíba 58.059-900, Brazil
| | - Gessenildo P. Rodrigues
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa, Paraíba 58.059-900, Brazil
| | - Glauco F. Bauerfeldt
- Departamento de Química, Instituto de Ciências Exatas, UFRRJ, Pavilhão Roberto Alvahydo (PQ), sala 44. km 7, Rodovia Br 465, Seropédica, Rio de Janeiro 23890-000, Brazil
| | - Elizete Ventura
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa, Paraíba 58.059-900, Brazil
| | | | - Silmar A. do Monte
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa, Paraíba 58.059-900, Brazil
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Abstract
The mechanism of the O2⋅− and H2O2 reaction (Haber–Weiss) under solvent‐free conditions has been characterized at the DFT and CCSD(T) level of theory to account for the ease of this reaction in the gas phase and the formation of two different set of products (Blanksby et al., Angew. Chem. Int. Ed. 2007, 46, 4948). The reaction is shown to proceed through an electron‐transfer process from the superoxide anion to hydrogen peroxide, along two pathways. While the O3⋅− + H2O products are formed from a spin‐allowed reaction (on the doublet surface), the preferred products, O⋅−(H2O)+3O2, are formed through a spin‐forbidden reaction as a result of a favorable crossing point between the doublet and quartet surface. Plausible reasons for the preference toward the latter set are given in terms of the characteristics of the minimum energy crossing point (MECP) and the stability of an intermediate formed (after the MECP) in the quartet surface. These unique results show that these two pathways are associated with a bifurcation, yielding spin‐dependent products.
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Affiliation(s)
- Ezequiel F V Leitão
- Departamento de Química Universidade Federal da ParaíbaJoão Pessoa, PB 58.059-900 Brazil
| | - Elizete Ventura
- Departamento de Química Universidade Federal da ParaíbaJoão Pessoa, PB 58.059-900 Brazil
| | - Miguel A F de Souza
- Instituto de Química Universidade Federal do Rio Grande do Norte Natal, RN 59072-970 Brazil
| | - José M Riveros
- Departamento de Química Fundamental Universidade de São Paulo Av. Prof. Lineu Prestes, 748 05508-000 São Paulo, SP, Brazil João Pessoa, PB, 58.059-900 Brazil
| | - Silmar A do Monte
- Departamento de Química Universidade Federal da ParaíbaJoão Pessoa, PB 58.059-900 Brazil
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8
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Rajic Z, Tovmasyan A, de Santana OL, Peixoto IN, Spasojevic I, do Monte SA, Ventura E, Rebouças JS, Batinic-Haberle I. Challenges encountered during development of Mn porphyrin-based, potent redox-active drug and superoxide dismutase mimic, MnTnBuOE-2-PyP 5+, and its alkoxyalkyl analogues. J Inorg Biochem 2017; 169:50-60. [PMID: 28131001 DOI: 10.1016/j.jinorgbio.2017.01.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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: 08/26/2016] [Revised: 12/21/2016] [Accepted: 01/03/2017] [Indexed: 11/28/2022]
Abstract
We disclose here the studies that preceded and guided the preparation of the metal-based, redox-active therapeutic Mn(III) meso-tetrakis(N-n-butoxyethylpyridyl)porphyrin, MnTnBuOE-2-PyP5+ (BMX-001), which is currently in Phase I/II Clinical Trials at Duke University (USA) as a radioprotector of normal tissues in cancer patients. N-substituted pyridylporphyrins are ligands for Mn(III) complexes that are among the most potent superoxide dismutase mimics thus far synthesized. To advance their design, thereby improving their physical and chemical properties and bioavailability/toxicity profiles, we undertook a systematic study on placing oxygen atoms into N-alkylpyridyl chains via alkoxyalkylation reaction. For the first time we show here the unforeseen structural rearrangement that happens during the alkoxyalkylation reaction by the corresponding tosylates. Comprehensive experimental and computational approaches were employed to solve the rearrangement mechanism involved in quaternization of pyridyl nitrogens, which, instead of a single product, led to a variety of mixed N-alkoxyalkylated and N-alkylated pyridylporphyrins. The rearrangement mechanism involves the formation of an intermediate alkyl oxonium cation in a chain-length-dependent manner, which subsequently drives differential kinetics and thermodynamics of competing N-alkoxyalkylation versus in situ N-alkylation. The use of alkoxyalkyl tosylates, of different length of alkyl fragments adjacent to oxygen atom, allowed us to identify the set of alkyl fragments that would result in the synthesis of a single compound of high purity and excellent therapeutic potential.
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Affiliation(s)
- Zrinka Rajic
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Artak Tovmasyan
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Otávio L de Santana
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil
| | - Isabelle N Peixoto
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil
| | - Ivan Spasojevic
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA; Duke Cancer Institute, Pharmaceutical Research Shared Resource, PK/PD Core Laboratory, Durham, NC 27710, United States
| | - Silmar A do Monte
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil
| | - Elizete Ventura
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil
| | - Júlio S Rebouças
- Departamento de Química, CCEN, Universidade Federal da Paraiba, João Pessoa, PB 58051-900, Brazil.
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA.
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de Medeiros VC, de Andrade RB, Leitão EFV, Ventura E, Bauerfeldt GF, Barbatti M, do Monte SA. Photochemistry of CH3Cl: Dissociation and CH···Cl Hydrogen Bond Formation. J Am Chem Soc 2015; 138:272-80. [PMID: 26653216 DOI: 10.1021/jacs.5b10573] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
State-of-the-art electronic structure calculations (MR-CISD) are used to map five different dissociation channels of CH3Cl along the C-Cl coordinate: (i) CH3(X̃(2)A2″) + Cl((2)P), (ii) CH3(3s(2)A1') + Cl((2)P), (iii) CH3(+)((1)A1') + Cl(-)((1)S), (iv) CH3(3p(2)E') + Cl((2)P), and (v) CH3(3p(2)A2″) + Cl((2)P). By the first time these latter four dissociation channels, accessible upon VUV absorption, are described. The corresponding dissociation limits, obtained at the MR-CISD+Q level, are 3.70, 9.50, 10.08, 10.76, and 11.01 eV. The first channel can be accessed through nσ* and n3s states, while the second channel can be accessed through n(e)3s, n(e)3p(σ), and σ3s states. The third channel, corresponding to the CH3(+) + Cl(-) ion-pair, is accessed through n(e)3p(e) states. The fourth is accessed through n(e)3p(e), n(e)3p(σ), and σ3p(σ), while the fifth through σ3p(e) and σ(CH)σ* states. The population of the diverse channels is controlled by two geometrical spots, where intersections between multiple states allow a cascade of nonadiabatic events. The ion-pair dissociation occurs through formation of CH3(+)···Cl(-)and H2CH(+)···Cl(-) intermediate complexes bound by 3.69 and 4.65 eV. The enhanced stability of the H2CH(+)···Cl(-) complex is due to a CH···Cl hydrogen bond. A time-resolved spectroscopic setup is proposed to detect those complexes.
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Affiliation(s)
- Vanessa C de Medeiros
- Departamento de Química, CCEN, Universidade Federal da Paraíba , João Pessoa, PB 58059-900, Brazil
| | - Railton B de Andrade
- Departamento de Química, CCEN, Universidade Federal da Paraíba , João Pessoa, PB 58059-900, Brazil
| | - Ezequiel F V Leitão
- Departamento de Química, CCEN, Universidade Federal da Paraíba , João Pessoa, PB 58059-900, Brazil
| | - Elizete Ventura
- Departamento de Química, CCEN, Universidade Federal da Paraíba , João Pessoa, PB 58059-900, Brazil
| | - Glauco F Bauerfeldt
- Departamento de Química, Instituto de Ciências Exatas, UFRRJ, Pavilhão Roberto Alvahydo (PQ) , sala 44. km 7, Rodovia Br 465, Seropédica, RJ 23890-000, Brazil
| | - Mario Barbatti
- Aix Marseille Université , CNRS, ICR UMR7273, 13397 Marseille, France
| | - Silmar A do Monte
- Departamento de Química, CCEN, Universidade Federal da Paraíba , João Pessoa, PB 58059-900, Brazil
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de Souza MAF, Ventura E, do Monte SA, Riveros JM, Longo RL. Revisiting the concept of the (a)synchronicity of diels-alder reactions based on the dynamics of quasiclassical trajectories. J Comput Chem 2015; 37:701-11. [DOI: 10.1002/jcc.24245] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 10/16/2015] [Accepted: 10/17/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Miguel A. F. de Souza
- Instituto De Química, Universidade Federal Do Rio Grande Do Norte; Natal Rio Grande do Norte 59072-970 Brazil
- Departamento De Química; CCEN, Universidade Federal Da Paraíba; João Pessoa Paraíba 58.059-900 Brazil
- Departamento De Química Fundamental; Universidade Federal De Pernambuco; Recife Pernambuco 50.740-560 Brazil
| | - Elizete Ventura
- Departamento De Química; CCEN, Universidade Federal Da Paraíba; João Pessoa Paraíba 58.059-900 Brazil
| | - Silmar A. do Monte
- Departamento De Química; CCEN, Universidade Federal Da Paraíba; João Pessoa Paraíba 58.059-900 Brazil
| | - José M. Riveros
- Instituto De Química, Universidade De São Paulo; Caixa Postal 26077 São Paulo 05599-970 Brazil
- Centro De Ciências Naturais E Humanas, Universidade Federal Do ABC; Rua Santa Adelia 166 Santo André, São Paulo 09210-170 Brazil
| | - Ricardo L. Longo
- Departamento De Química Fundamental; Universidade Federal De Pernambuco; Recife Pernambuco 50.740-560 Brazil
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11
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Proenza YG, de Souza MAF, Ventura E, do Monte SA, Longo RL. Assessment of density-functionals for describing the X(-) + CH3ONO2 gas-phase reactions with X = F, OH, CH2CN. Phys Chem Chem Phys 2015; 16:26769-78. [PMID: 25372179 DOI: 10.1039/c4cp03674c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [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
The energetics of the ECO2, SN2@C and SN2@N channels of X(-) + CH3ONO2 (X = F, OH, CH2CN) gas-phase reactions were computed using the CCSD(T)/CBS method. This benchmark extends a previous study with X = OH [M. A. F. de Souza et al., J. Am. Chem. Soc., 2012, 134, 19004] and was used to ascertain the accuracy and robustness of nineteen density-functionals for describing these potential energy profiles (PEP) as well as the kinetic product distributions obtained from RRKM calculations. Assessments were based on the mean unsigned error (MUE), the mean signed error (MSE), the #best : #worst (BW) criterion and the statistical confidence interval (CI) for the MSE. In general, double-hybrid (DH) functionals perform better than the range-separated ones, and both are better than the global-hybrid functionals. Based on the MUE and CI criteria the B2GPPLYP, B2PLYP, M08-SO, BMK, ωB97X-D, CAM-B3LYP, M06, M08-HX, ωB97X and B97-K functionals show the best performance in the description of these PEPs. Within this set, the B2GPPLYP functional is the most accurate and robust. The RRKM results indicate that the DHs are the best for describing the selectivities of these reactions. Compared to CCSD(T), the B2PLYP method has a relative error of only ca. 1% for the selectivity and the accuracy to provide the correct conclusion concerning the nonstatistical behavior of these reactions.
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Affiliation(s)
- Yaicel G Proenza
- Departamento de Química Fundamental, CCEN, Universidade Federal de Pernambuco, Cidade Universitária, Recife, PE 50.740-560, Brazil.
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de Souza MAF, Ventura E, do Monte SA, Riveros JM, Longo RL. Dynamic effects dictate the mechanism and selectivity of dehydration-rearrangement reactions of protonated alcohols [Me2 (R)CCH(OH2 )Me](+) (R=Me, Et, iPr) in the gas phase. Chemistry 2014; 20:13742-54. [PMID: 25179304 DOI: 10.1002/chem.201402617] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [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: 03/14/2014] [Indexed: 11/12/2022]
Abstract
The gas-phase dehydration-rearrangement (DR) reactions of protonated alcohols [Me2 (R)CCH(OH2 )Me](+) [R=Me (ME), Et (ET), and iPr (I-PR)] were studied by using static approaches (intrinsic reaction coordinate (IRC), Rice-Ramsperger-Kassel-Marcus theory) and dynamics (quasiclassical trajectory) simulations at the B3LYP/6-31G(d) level of theory. The concerted mechanism involves simultaneous water dissociation and alkyl migration, whereas in the stepwise reaction pathway the dehydration step leads to a secondary carbocation intermediate followed by alkyl migration. Internal rotation (IR) can change the relative position of the migrating alkyl group and the leaving group (water), so distinct products may be obtained: [Me(R)CCH(Me)Me⋅⋅⋅OH2 ](+) and [Me(Me)CCH(R)Me⋅⋅⋅OH2 ](+) . The static approach predicts that these reactions are concerted, with the selectivity towards these different products determined by the proportion of the conformers of the initial protonated alcohols. These selectivities are explained by the DR processes being much faster than IR. These results are in direct contradiction with the dynamics simulations, which indicate a predominantly stepwise mechanism and selectivities that depend on the alkyl groups and dynamics effects. Indeed, despite the lifetimes of the secondary carbocations being short (<0.5 ps), IR can take place and thus provide a rich selectivity. These different selectivities, particularly for ET and I-PR, are amenable to experimental observation and provide evidence for the minor role played by potential-energy surface and the relevance of the dynamics effects (non-IRC pathways, IR) in determining the reaction mechanisms and product distribution (selectivity).
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Affiliation(s)
- Miguel A F de Souza
- Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50.740-560, Recife, PE (Brazil), Fax:(+55) 83-21268000; Instituto de Química, Universidade de São Paulo, Caixa Postal 26077, 05599-970, São Paulo, SP (Brazil)
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Abstract
In this work ten singlet and nine triplet states are studied through multi-reference configuration interactions with singles and doubles (MR-CISD), including Davidson extensivity correction (MR-CISD+Q).
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Affiliation(s)
| | - Silmar A. do Monte
- Departamento de Química
- CCEN
- Universidade Federal da Paraíba
- João Pessoa, Brazil
| | - Elizete Ventura
- Departamento de Química
- CCEN
- Universidade Federal da Paraíba
- João Pessoa, Brazil
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do Monte SA, Ventura E, de Andrade RB, Fragoso WD. Control of ionic properties of N-nitrosodimethylamine through hydrogen substitution by fluorine atoms. Struct Chem 2012. [DOI: 10.1007/s11224-012-9945-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Monte SAD, Ventura E. A importância do método de Hartree no ensino de química quântica. QUIM NOVA 2011. [DOI: 10.1590/s0100-40422011000300028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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do Monte SA, Ventura E, da Costa TF, de Santana SR. Ab initio and DFT conformational study on nitrosamine (H2N–N=O) and N-Nitrosodimethylamine [(CH3)2N–N=O]. Struct Chem 2010. [DOI: 10.1007/s11224-010-9721-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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de Souza MAF, Ventura E, Araújo RCMU, Ramos MN, do Monte SA. CASSCF and multireference CI with singles and doubles study of low-lying valence and Rydberg states of 2H-tetrazole. J Comput Chem 2009; 30:1075-81. [PMID: 18942735 DOI: 10.1002/jcc.21133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Miguel A F de Souza
- Departamento de Química, CCEN, Universidade Federal da Paraíba, João Pessoa/PB 58059-900 Brazil
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Mariano A, Ventura E, Monte SAD, Braga CF, Carvalho AB, Araújo RCMU, Santana OL. O ensino de reações orgânicas usando química computacional: I. reações de adição eletrofílica a alquenos. QUIM NOVA 2008. [DOI: 10.1590/s0100-40422008000500055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Lucena JR, Ventura E, do Monte SA, Araújo RCMU, Ramos MN, Fausto R. Dissociation of ground and nσ* states of CF3Cl using multireference configuration interaction with singles and doubles and with multireference average quadratic coupled cluster extensivity corrections. J Chem Phys 2007; 127:164320. [DOI: 10.1063/1.2800020] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tavares AM, da Silva WLV, Lopes KC, Ventura E, Araújo RCMU, do Monte SA, da Silva JBP, Ramos MN. A theoretical study of hydrogen complexes of the XH-pi type between propyne and HF, HCL or HCN. Spectrochim Acta A Mol Biomol Spectrosc 2006; 64:412-7. [PMID: 16330245 DOI: 10.1016/j.saa.2005.07.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Accepted: 07/16/2005] [Indexed: 05/05/2023]
Abstract
The present manuscript reports a systematic investigation of the basis set dependence of some properties of hydrogen-bonded (pi type) complexes formed by propyne and a HX molecule, where X=F, Cl and CN. The calculations have been performed at Hartree-Fock, MP2 and B3LYP levels. Geometries, H-bond energies and vibrational have been considered. The more pronounced effects on the structural parameters of the isolated molecules, as a result of complexation, are verified on RCtriple bondC and HX bond lengths. As compared to double-zeta (6-31G**), triple-zeta (6-311G**) basis set leads to an increase of RCtriple bondC bond distance, at all three computational levels. In the case where diffuse functions are added to both hydrogen and 'heavy' atoms, the effect is more pronounced. The propyne-HX structural parameters are quite similar to the corresponding parameters of acetylene-HX complexes, at all levels. The largest difference is obtained for hydrogen bond distance, RH, with a smaller value for propyne-HX complex, indicating a stronger bond. Concerning the electronic properties, the results yield the following ordering for H-bond energies, DeltaE: propynecdots, three dots, centeredHF>propynecdots, three dots, centeredHCl>propynecdots, three dots, centeredHCN. It is also important to point out that the inclusion of BSSE and zero-point energies (ZPE) corrections cause significant changes on DeltaE. The smaller effect of ZPE is obtained for propynecdots, three dots, centeredHCN at HF/6-311++G** level, while the greatest difference is obtained at MP2/6-31G** level for propynecdots, three dots, centeredHF system. Concerning the IR vibrational it was obtained that larger shift can be associated with stronger hydrogen bonds. The more pronounced effect on the normal modes of the isolated molecule after the complexation is obtained for HX stretching frequency, which is shifted downward.
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Affiliation(s)
- Alessandra M Tavares
- Departamento de Química, Universidade Federal da Paraíba, Rua José Simões Araújo 352 apto 501, Bessa, 58036-300 João Pessoa, PB, Brazil
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Ramos MN, Lopes KC, Silva WLV, Tavares AM, Castriani FA, do Monte SA, Ventura E, Araújo RCMU. An ab initio study of the C2H2-HF, C2H(CH3)-HF and C2(CH3)2-HF hydrogen-bonded complexes. Spectrochim Acta A Mol Biomol Spectrosc 2006; 63:383-90. [PMID: 16427352 DOI: 10.1016/j.saa.2005.05.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 04/27/2005] [Accepted: 05/14/2005] [Indexed: 05/06/2023]
Abstract
MP2/6-31++G** and B3LYP/6-31++G** ab initio molecular orbital calculations have been performed in order to obtain molecular geometries, binding energies and vibrational properties of the C2H2-HF, C2H(CH3)-HF and C2(CH3)2-HF H-bonded complexes. As expected, the more pronounced effects on the structural properties of the isolated molecules due to complexation was verified for the C[triple bond]C and H-F bond lengths, which are directly involved in the H-bond formation. These bond distances increased after complexation. BSSE uncorrected B3LYP binding energies are always lower than the corresponding MP2 values. However, the opposite trend has been verified after BSSE correction by the counterpoise method since it is much lower at B3LYP than at MP2 level. The binding energies for these complexes as well as for the HF acid submolecule modes (the HF stretching and vibrational frequency modes) showed an increasing hydrogen-bonding strength with increasing methyl substitution. The splitting in the HF in-plane and out-of-plane bending modes reflects the anisotropy in the hydrogen-bonding interaction with the pi system of the C[triple bond]C bond. The H-F stretching frequency is shifted downward after complexation and it increases with the methyl substitution. The IR intensities of the HF acid submolecule fundamentals are adequately interpreted through the atomic polar tensor of the hydrogen atom using the charge-charge flux-overlap model. The skeletal stretching modes of the Alkyne submolecule are decreased in the complex. The new vibrational modes arising from complexation show several interesting features.
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Affiliation(s)
- Mozart N Ramos
- Departamento de Química Fundamental, Universidade Federal de Pernambuco (UFPE), Rua Jose Simoes Araujo 352 apto 501, 50739-901, Recife (PE), Brasil.
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do Monte SA, Ventura E, da Gama A. Ab-initio study of the electronic factor (Δ) conformational dependence in [CH2–(phenylene)n–CH2]− electron transfer model systems. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2005.01.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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do Monte SA. Effects of Zn and substituents(methyl and p-tolyl) on the decay of electron transfer rates in porphyrin–benzene–(bicyclo[2.2.2]octane) –quinone (n=0,1,2) systems. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)00163-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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