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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] [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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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] [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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Tang X, Lin X, Zhang W, Garcia GA, Nahon L. Double imaging photoelectron photoion coincidence sheds new light on the dissociation of energy-selected CH3Cl+ ions. Phys Chem Chem Phys 2016; 18:23923-31. [PMID: 27524637 DOI: 10.1039/c6cp04161b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dissociation mechanisms of CH3Cl+ have been probed to be state-specific and the umbrella mode of the CH3+ fragments is assigned.
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Affiliation(s)
- Xiaofeng Tang
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
| | - Xiaoxiao Lin
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
| | - Weijun Zhang
- Laboratory of Atmospheric Physico-Chemistry
- Anhui Institute of Optics and Fine Mechanics
- Chinese Academy of Sciences
- Hefei
- China
| | | | - Laurent Nahon
- Synchrotron SOLEIL
- L’Orme des Merisiers
- 91192 Gif sur Yvette
- France
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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] [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 Medeiros VC, do Monte SA, Ventura E. Valence and Rydberg states of CH3Cl: a MR-CISD study. RSC Adv 2014. [DOI: 10.1039/c4ra10567b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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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Donovan RJ, Hennessy JT, Lawley KP, Ridley T. A critical re-assignment of the Rydberg states of iodomethane based on new polarization data. J Chem Phys 2013; 138:134308. [DOI: 10.1063/1.4798972] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Locht R, Jochims H, Leyh B. The vacuum UV photoabsorption spectroscopy of the geminal ethylene difluoride (1,1-C2H2F2). The vibrational structure and its analysis. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2012.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Shao Z, Li H, Zhang S, Li J, Dai Z, Mo Y, Bae YJ, Kim MS. The Jahn-Teller effect in CH 3 Cl +(X̃E2): A combined high-resolution experimental measurement and ab initio theoretical study. J Chem Phys 2012; 136:064308. [DOI: 10.1063/1.3679655] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Grütter M, Merkt F. Photoelectron spectroscopic study of the E ⊗ e Jahn–Teller effect in the presence of a tunable spin–orbit interaction. II. Rovibronic analysis of the2E ground state of CH3CI+. Mol Phys 2011. [DOI: 10.1080/00268976.2011.609143] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Simpson MJ, Tuckett RP. Vacuum-UV negative photoion spectroscopy of gas-phase polyatomic molecules. INT REV PHYS CHEM 2011. [DOI: 10.1080/0144235x.2011.581000] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Rogers NJ, Simpson MJ, Tuckett RP, Dunn KF, Latimer CJ. Vacuum-UV negative photoion spectroscopy of CH3F, CH3Cl and CH3Br. Phys Chem Chem Phys 2010; 12:10971-80. [DOI: 10.1039/c0cp00234h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Medium and high resolution vacuum UV photoabsorption spectroscopy of methyl iodide (CH3I) and its deuterated isotopomers CD3I and CH2DI. A Rydberg series analysis. Chem Phys 2009. [DOI: 10.1016/j.chemphys.2009.09.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Locht R, Leyh B, Dehareng D, Jochims H, Baumgärtel H. The vacuum UV photoabsorption spectroscopy of vinyl fluoride (C2H3F): The vibrational fine structure and its analysis. Chem Phys 2009. [DOI: 10.1016/j.chemphys.2009.06.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Similarities in the continuous states of the group of halogenated methanes CH3X (X=Cl, Br, I): Molecular quantum defect orbital (MQDO) cross section calculations for allowed photoionization channels. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.05.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Holland D, Powis I, Öhrwall G, Karlsson L, von Niessen W. A study of the photoionisation dynamics of chloromethane and iodomethane. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2006.03.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Xi HW, Huang MB. Bromine-loss and hydrogen-loss dissociations in low-lying electronic states of the CH3Br+ ion studied using multiconfiguration second-order perturbation theory. J Phys Chem A 2006; 110:8167-73. [PMID: 16805504 DOI: 10.1021/jp056138r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Complete active space self-consistent field (CASSCF) and multiconfiguration second-order perturbation theory (CASPT2) calculations with an ANO-RCC basis were performed for the 1(2)A', 1(2)A", 2(2)A', and 2(2)A" states of the CH3Br+ ion. The 1(2)A' state is predicted to be the ground state. The 2(2)A' state is predicted to be a bound state. The adiabatic and vertical excitation energies and the relative energies at the molecular geometry were calculated, and the energetic results for 2(2)A' and 2(2)A" are in reasonable agreement with the experimental data. Potential energy curves (PECs) for Br-loss and H-loss dissociations from the four C(s) states were calculated at the CASPT2//CASSCF level and the electronic states of the CH3(+) and CH2Br(+) ions as the dissociation products were determined by checking the relative energies and geometries of the asymptote products along the PECs. In the Br-loss dissociation, the 1(2)A', 1(2)A", and 2(2)A' states correlate with CH3(+) (X1A1') and the 2(2)A" state correlates with CH3(+) (1(3)A"). The energy increases monotonically with the R(C-Br) value along the four Br-loss PECs. In the H-loss dissociation the 1(2)A', 1(2)A", 2(2)A', and 2(2)A" states correlate with the X(1)A(1), 1(3)A", 1(3)A', and 1(1)A" states (1(3)A' lying above 1(1)A") of CH2Br(+), respectively. Along the 2(2)A" H-loss PEC there is an energy barrier and the CASSCF wave functions at large R(C-H) values have shake-up ionization character. Along the 2(2)A' H-loss PEC there are an energy barrier and a minimum. At the end of the present paper we present a comprehensive review on the electronic states and the X-loss and H-loss dissociations of the CH(3)X(+) (X = F, Cl, and Br) ions on the basis of our previous studies and the present study.
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Affiliation(s)
- Hong-Wei Xi
- College of Chemistry and Chemical Engineering, Graduate University, Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049, People's Republic of China
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Eden S, Limão-Vieira P, Hoffmann S, Mason N. VUV photoabsorption in CF3X (X=Cl, Br, I) fluoro-alkanes. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2005.09.040] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Locht R, Leyh B, Dehareng D, Jochims H, Baumgärtel H. The vacuum UV photoabsorption spectrum of methyl bromide (CH3Br) and its perdeuterated isotopomer CD3Br: a vibrational analysis. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2005.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Locht R, Leyh B, Jochims H, Baumgärtel H. The vacuum UV photoabsorption spectrum of methyl bromide (CH3Br) and its perdeuterated isotopomer CD3Br: a Rydberg series analysis. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2005.06.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Cossart-Magos C, Jungen M, Stalder J, Launay F. High-resolution absorption spectrum of jet-cooled CH3Cl between 70 000 and 85000cm−1: New assignments. J Chem Phys 2005; 123:104302. [PMID: 16178592 DOI: 10.1063/1.1950671] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The absorption spectrum of jet-cooled CH(3)Cl was photographed from 165 to 117 nm (or 60,000 - 85,000 cm(-1), 7.5-10.5 eV) at a resolution limit of 0.0008 nm (0.3-0.6 cm(-1) or 0.04-0.08 meV). Even in the best structured region of the spectrum, from 70,000 to 85,000 cm(-1) (8.7-10.5 eV), observed bandwidths (full width at half maximum) are large, from 50 to 150 cm(-1). No rotational feature could be resolved. The spectrum is dominated by two strong bands near 9 eV, 140 nm, the D and E bands of Mulliken [J. Chem. Phys. 8, 382 (1940)] or the spectral region D of Price [J. Chem. Phys.4, 539 (1936)]. Their relative intensity is incompatible with previous assignments, namely, to a triplet and a singlet state belonging to the same configuration. On the basis of the present ab initio calculations, those bands are now assigned to two singlet states, the (1)A(1) and (1)E excited states resulting from the 2e(3)4pe Rydberg configuration. The present calculations also reveal that the two (1)E states issued from 2e(3)4sa(1) and 2e(3)4pa(1) are quasidegenerate and strongly mixed. They should be assigned to the two broad bands near 8 eV, 160 nm, the B and C bands of Mulliken and Price. Three vibrational modes are observed to be active: the CCl bond stretch nu(3)(a(1)), and the CH(3) umbrella and rocking vibrations, respectively, nu(2)(a(1)) and nu(6)(e). The fundamental frequencies deduced are well within the ranges defined by the corresponding values in the neutral and ion ground states. The possibility of a dynamical Jahn-Teller effect induced by the nu(6)(e) vibrational mode in the (1)E Rydberg states is discussed.
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Affiliation(s)
- Claudina Cossart-Magos
- Laboratoire de Photophysique Moléculaire du Centre National de la Recherche Scientifique (CNRS), Institut de Physico-Chimie Moléculaire, Université de Paris-Sud, Orsay , France.
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Locht R, Leyh B, Hoxha A, Dehareng D, Jochims H, Baumgärtel H. The vacuum UV photoabsorption spectrum of methyl chloride (CH3Cl) and its perdeuterated isotopomer CD3Cl. Chem Phys 2001. [DOI: 10.1016/s0301-0104(01)00465-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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