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Gu J, Lee S, Eom S, Ki H, Choi EH, Lee Y, Nozawa S, Adachi SI, Kim J, Ihee H. Structural Dynamics of C 2F 4I 2 in Cyclohexane Studied via Time-Resolved X-ray Liquidography. Int J Mol Sci 2021; 22:9793. [PMID: 34575954 PMCID: PMC8469616 DOI: 10.3390/ijms22189793] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 11/28/2022] Open
Abstract
The halogen elimination of 1,2-diiodoethane (C2H4I2) and 1,2-diiodotetrafluoroethane (C2F4I2) serves as a model reaction for investigating the influence of fluorination on reaction dynamics and solute-solvent interactions in solution-phase reactions. While the kinetics and reaction pathways of the halogen elimination reaction of C2H4I2 were reported to vary substantially depending on the solvent, the solvent effects on the photodissociation of C2F4I2 remain to be explored, as its reaction dynamics have only been studied in methanol. Here, to investigate the solvent dependence, we conducted a time-resolved X-ray liquidography (TRXL) experiment on C2F4I2 in cyclohexane. The data revealed that (ⅰ) the solvent dependence of the photoreaction of C2F4I2 is not as strong as that observed for C2H4I2, and (ⅱ) the nongeminate recombination leading to the formation of I2 is slower in cyclohexane than in methanol. We also show that the molecular structures of the relevant species determined from the structural analysis of TRXL data provide an excellent benchmark for DFT calculations, especially for investigating the relevance of exchange-correlation functionals used for the structural optimization of haloalkanes. This study demonstrates that TRXL is a powerful technique to study solvent dependence in the solution phase.
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Affiliation(s)
- Jain Gu
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea; (J.G.); (S.L.); (S.E.); (H.K.); (E.H.C.); (Y.L.)
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Seonggon Lee
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea; (J.G.); (S.L.); (S.E.); (H.K.); (E.H.C.); (Y.L.)
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Seunghwan Eom
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea; (J.G.); (S.L.); (S.E.); (H.K.); (E.H.C.); (Y.L.)
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Hosung Ki
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea; (J.G.); (S.L.); (S.E.); (H.K.); (E.H.C.); (Y.L.)
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Eun Hyuk Choi
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea; (J.G.); (S.L.); (S.E.); (H.K.); (E.H.C.); (Y.L.)
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Yunbeom Lee
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea; (J.G.); (S.L.); (S.E.); (H.K.); (E.H.C.); (Y.L.)
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Korea
| | - Shunsuke Nozawa
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba 305-0801, Ibaraki, Japan; (S.N.); (S.-i.A.)
- Department of Materials Structure Science, School of High Energy Accelerator Science, The Graduate University for Advanced Studies, 1-1 Oho, Tsukuba 305-0801, Ibaraki, Japan
| | - Shin-ichi Adachi
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba 305-0801, Ibaraki, Japan; (S.N.); (S.-i.A.)
- Department of Materials Structure Science, School of High Energy Accelerator Science, The Graduate University for Advanced Studies, 1-1 Oho, Tsukuba 305-0801, Ibaraki, Japan
| | - Jeongho Kim
- Department of Chemistry, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Korea;
| | - Hyotcherl Ihee
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea; (J.G.); (S.L.); (S.E.); (H.K.); (E.H.C.); (Y.L.)
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 34141, Korea
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Anderson CP, Spears KG, Wilson KR, Sension RJ. Solvent dependent branching between C-I and C-Br bond cleavage following 266 nm excitation of CH2BrI. J Chem Phys 2014; 139:194307. [PMID: 24320326 DOI: 10.1063/1.4829899] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
It is well known that ultraviolet photoexcitation of halomethanes results in halogen-carbon bond cleavage. Each halogen-carbon bond has a dominant ultraviolet (UV) absorption that promotes an electron from a nonbonding halogen orbital (nX) to a carbon-halogen antibonding orbital (σ*C-X). UV absorption into specific transitions in the gas phase results primarily in selective cleavage of the corresponding carbon-halogen bond. In the present work, broadband ultrafast UV-visible transient absorption studies of CH2BrI reveal a more complex photochemistry in solution. Transient absorption spectra are reported spanning the range from 275 nm to 750 nm and 300 fs to 3 ns following excitation of CH2BrI at 266 nm in acetonitrile, 2-butanol, and cyclohexane. Channels involving formation of CH2Br + I radical pairs, iso-CH2Br-I, and iso-CH2I-Br are identified. The solvent environment has a significant influence on the branching ratios, and on the formation and stability of iso-CH2Br-I. Both iso-CH2Br-I and iso-CH2I-Br are observed in cyclohexane with a ratio of ~2.8:1. In acetonitrile this ratio is 7:1 or larger. The observation of formation of iso-CH2I-Br photoproduct as well as iso-CH2Br-I following 266 nm excitation is a novel result that suggests complexity in the dissociation mechanism. We also report a solvent and concentration dependent lifetime of iso-CH2Br-I. At low concentrations the lifetime is >4 ns in acetonitrile, 1.9 ns in 2-butanol and ~1.4 ns in cyclohexane. These lifetimes decrease with higher initial concentrations of CH2BrI. The concentration dependence highlights the role that intermolecular interactions can play in the quenching of unstable isomers of dihalomethanes.
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Affiliation(s)
- Christopher P Anderson
- Department of Chemistry and Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
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Fdez. Galván I, Xiao HY, Navizet I, Liu YJ, Lindh R. S0→ S3transition in recombination products of photodissociated dihalomethanes. Mol Phys 2013. [DOI: 10.1080/00268976.2013.832429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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4
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Preston TJ, Shaloski MA, Crim FF. Probing the Photoisomerization of CHBr3 and CHI3 in Solution with Transient Vibrational and Electronic Spectroscopy. J Phys Chem A 2013; 117:2899-907. [DOI: 10.1021/jp310737d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas J. Preston
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706,
United States
| | - Michael A. Shaloski
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706,
United States
| | - F. Fleming Crim
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706,
United States
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5
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Pal SK, Mereshchenko AS, Butaeva EV, El-Khoury PZ, Tarnovsky AN. Global sampling of the photochemical reaction paths of bromoform by ultrafast deep-UV through near-IR transient absorption and ab initio multiconfigurational calculations. J Chem Phys 2013; 138:124501. [DOI: 10.1063/1.4789268] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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6
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Shalit A, Prior Y. Time resolved polarization dependent single shot four wave mixing. Phys Chem Chem Phys 2012; 14:13989-96. [DOI: 10.1039/c2cp42112g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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ZHAO CUNYUAN, WANG DONGQI, PHILLIPS DAVIDLEE. DENSITY FUNCTIONAL STUDY OF SELECTED MONO-ZINC AND GEM-DIZINC RADICAL CARBENOID CYCLOPROPANATION REACTIONS: OBSERVATION OF AN EFFICIENT RADICAL ZINC CARBENOID CYCLOPROPANATION REACTION AND THE INFLUENCE OF THE LEAVING GROUP ON RING CLOSURE. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633603000549] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We report a theoretical study of the cyclopropanation reactions of EtZnCHI, (EtZn)2CH EtZnCHZnI, and EtZnCIZnI radicals with ethylene. The mono-zinc and gem-dizinc radical carbenoids can undergo cyclopropanation reactions with ethylene via a two-step reaction mechanism similar to that previously reported for the CH2I and IZnCH2 radicals. The barrier for the second reaction step (ring closure) was found to be highly dependent on the leaving group of the cyclopropanation reaction. In some cases, the (di)zinc carbenoid radical undergoes cyclopropanation via a low barrier of about 5–7 kcal/mol on the second reaction step and this is lower than the CH2I radical reaction which has a barrier of about 13.5 kcal/mol for the second reaction step. Our results suggest that in some cases, zinc radical carbenoid species have cyclopropanation reaction barriers that can be competitive with their related molecular Simmons-Smith carbenoid species reactions and produce somewhat different cyclopropanated products and leaving groups.
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Affiliation(s)
- CUNYUAN ZHAO
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
| | - DONG-QI WANG
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
| | - DAVID LEE PHILLIPS
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
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8
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El-Khoury PZ, Pal SK, Mereshchenko AS, Tarnovsky AN. The formation and back isomerization of iso-H2C–Br–Br on a 100-ps time scale following 255-nm excitation of CH2Br2 in acetonitrile. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.04.065] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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9
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Carrier SL, Preston TJ, Dutta M, Crowther AC, Crim FF. Ultrafast Observation of Isomerization and Complexation in the Photolysis of Bromoform in Solution. J Phys Chem A 2009; 114:1548-55. [DOI: 10.1021/jp908725t] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stacey L. Carrier
- Department of Chemistry University of Wisconsin—Madison, Madison, Wisconsin 53706
| | - Thomas J. Preston
- Department of Chemistry University of Wisconsin—Madison, Madison, Wisconsin 53706
| | - Maitreya Dutta
- Department of Chemistry University of Wisconsin—Madison, Madison, Wisconsin 53706
| | - Andrew C. Crowther
- Department of Chemistry University of Wisconsin—Madison, Madison, Wisconsin 53706
| | - F. Fleming Crim
- Department of Chemistry University of Wisconsin—Madison, Madison, Wisconsin 53706
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10
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Liu Y, Xiao H, Sun M, Fang W. Spin-orbitAb initioinvestigation of the photodissociation of dibromomethane in the gas and solution phases. J Comput Chem 2008; 29:2513-9. [DOI: 10.1002/jcc.21008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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11
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Kong Q, Wulff M, Lee JH, Bratos S, Ihee H. Photochemical Reaction Pathways of Carbon Tetrabromide in Solution Probed by Picosecond X-ray Diffraction. J Am Chem Soc 2007; 129:13584-91. [DOI: 10.1021/ja073503e] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Qingyu Kong
- Contribution from the European Synchrotron Radiation Facility, Grenoble Cedex 38043, BP 220, France, National Creative Research Initiative Center for Time-Resolved Diffraction, Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Republic of Korea, and Laboratoire de Physique, Théorique des Liquides, Université Pierre et Marie Curie, Case Courrier 121, 4 Place Jussieu, Paris Cedex 75252, France
| | - Michael Wulff
- Contribution from the European Synchrotron Radiation Facility, Grenoble Cedex 38043, BP 220, France, National Creative Research Initiative Center for Time-Resolved Diffraction, Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Republic of Korea, and Laboratoire de Physique, Théorique des Liquides, Université Pierre et Marie Curie, Case Courrier 121, 4 Place Jussieu, Paris Cedex 75252, France
| | - Jae Hyuk Lee
- Contribution from the European Synchrotron Radiation Facility, Grenoble Cedex 38043, BP 220, France, National Creative Research Initiative Center for Time-Resolved Diffraction, Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Republic of Korea, and Laboratoire de Physique, Théorique des Liquides, Université Pierre et Marie Curie, Case Courrier 121, 4 Place Jussieu, Paris Cedex 75252, France
| | - Savo Bratos
- Contribution from the European Synchrotron Radiation Facility, Grenoble Cedex 38043, BP 220, France, National Creative Research Initiative Center for Time-Resolved Diffraction, Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Republic of Korea, and Laboratoire de Physique, Théorique des Liquides, Université Pierre et Marie Curie, Case Courrier 121, 4 Place Jussieu, Paris Cedex 75252, France
| | - Hyotcherl Ihee
- Contribution from the European Synchrotron Radiation Facility, Grenoble Cedex 38043, BP 220, France, National Creative Research Initiative Center for Time-Resolved Diffraction, Department of Chemistry and School of Molecular Science (BK21), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Republic of Korea, and Laboratoire de Physique, Théorique des Liquides, Université Pierre et Marie Curie, Case Courrier 121, 4 Place Jussieu, Paris Cedex 75252, France
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12
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Kong Q, Wulff M, Bratos S, Vuilleumier R, Kim J, Ihee H. Structure of the photodissociation products of CCl4, CBr4, and CI4 in solution studied by DFT and ab initio calculations. J Phys Chem A 2007; 110:11178-87. [PMID: 16986853 DOI: 10.1021/jp062919w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Various molecular species that can be populated during the photoreaction of carbon tetrahalides CX(4) (X = Cl, Br, I) in the gas phase and in solution have been studied by ab initio and density functional theory (DFT) calculations. Geometries, energies, and vibrational frequencies of CX(4), CX(3), CX(2), C(2)X(6), C(2)X(5), C(2)X(4), X(2), and the isomer X(2)CX-X were calculated and transition states connecting these species were characterized. Spin-orbit DFT (SODFT) computations were also performed to include the relativistic effects, which cannot be neglected for Br and I atoms. The calculated potential energy surfaces satisfactorily describe the reactions of the photoexcited CX(4) molecules. In the gas phase, the initial C-X bond rupture in CX(4) is followed by secondary C-X breakage in the CX(3) radical, leading to CX(2) and 2X, and the formation of C(2)X(6) or C(2)X(4) through bimolecular recombination of the CX(3) or CX(2) radicals is favored thermodynamically. In solution, by contrast, the X(2)CX-X isomer is formed via X-X binding, and two CX(3) radicals recombine nongeminately to form C(2)X(6), which then dissociates into C(2)X(4) and X(2) through C(2)X(5). The Raman intensities and the vibrational frequencies, as well as the absorption spectra and oscillator strengths of the Br(2)CBr-Br isomer in the gas phase and in various solvents were computed and the calculated absorption and Raman spectra of the Br(2)CBr-Br isomer in various solutions are in good agreement with the experimental data. The natural population analysis indicates that the Br(2)CBr-Br isomer corresponds to the recently reported solvent-stabilized solvated ion pair (CBr(3)(+)//Br(-))(solv) in the highly polar alcohol solvent. The singlet-triplet energy separations of the CX(2) radicals in the gas phase and in solution were evaluated with high level computational methods, and the optimized geometric parameters are in good agreement with the experimental results. The geometric and energetic differences between the singlet and triplet states were explained by the electronic properties of the CX(2) radicals. C(2)X(4), C(2)X(5), and C(2)X(6) (X = Br, I) in the gas phase and in solution were optimized at different computational levels, and the optimized geometric parameters of C(2)I(4) are in very good agreement with the experimental data.
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Affiliation(s)
- Qingyu Kong
- European Synchrotron Radiation Facility, Grenoble Cedex 38043, BP 220, France.
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13
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Kwok WM, Zhao C, Guan X, Li YL, Du Y, Phillips DL. Efficient dehalogenation of polyhalomethanes and production of strong acids in aqueous environments: Water-catalyzed O–H-insertion and HI-elimination reactions of isodiiodomethane (CH2I–I) with water. J Chem Phys 2004; 120:9017-32. [PMID: 15267837 DOI: 10.1063/1.1701699] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A combined experimental and theoretical study of the ultraviolet photolysis of CH2I2 in water is reported. Ultraviolet photolysis of low concentrations of CH2I2 in water was experimentally observed to lead to almost complete conversion into CH2(OH)2 and 2HI products. Picosecond time-resolved resonance Raman spectroscopy experiments in mixed water/acetonitrile solvents (25%-75% water) showed that appreciable amounts of isodiiodomethane (CH2I-I) were formed within several picoseconds and the decay of the CH2I-I species became substantially shorter with increasing water concentration, suggesting that CH2I-I may be reacting with water. Ab initio calculations demonstrate the CH2I-I species is able to react readily with water via a water-catalyzed O--H-insertion and HI-elimination reaction followed by its CH2I(OH) product undergoing a further water-catalyzed HI-elimination reaction to make a H2C=O product. These HI-elimination reactions produce the two HI leaving groups observed experimentally and the H2C=O product further reacts with water to produce the other final CH2(OH)2 product observed in the photochemistry experiments. These results suggest that CH2I-I is the species that reacts with water to produce the CH2(OH)2 and 2HI products seen in the photochemistry experiments. The present study demonstrates that ultraviolet photolysis of CH2I2 at low concentration leads to efficient dehalogenation and release of multiple strong acid (HI) leaving groups. Some possible ramifications for the decomposition of polyhalomethanes and halomethanols in aqueous environments as well as the photochemistry of polyhalomethanes in the natural environment are briefly discussed.
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Affiliation(s)
- Wai Ming Kwok
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, China
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Chiang SY, Fang YS, Sankaran K, Lee YP. Experimental and quantum-chemical studies on photoionization and dissociative photoionization of CH2Br2. J Chem Phys 2004; 120:3270-6. [PMID: 15268481 DOI: 10.1063/1.1641010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The dissociative photoionization of CH2Br2 in a region approximately 10-24 eV was investigated with photoionization mass spectroscopy using a synchrotron radiation source. An adiabatic ionization energy of 10.25 eV determined for CH2Br2 agrees satisfactorily with predictions of 10.26 and 10.25 eV with G2 and G3 methods, respectively. Observed major fragment ions CH2Br+, CHBr+, and CBr+ show appearance energies at 11.22, 12.59, and 15.42 eV, respectively; minor fragment ions CHBr2+, Br+, and CH2+ appear at 12.64, 15.31, and 16.80 eV, respectively. Energies for formation of observed fragment ions and their neutral counterparts upon ionization of CH2Br2 are computed with G2 and G3 methods. Dissociative photoionization channels associated with six observed fragment ions are proposed based on comparison of determined appearance energies and predicted energies. An upper limit of DeltaH0f,298(CHBr+) < or = 300.7 +/- 1.5 kcal mol(-1) is derived experimentally; the adiabatic ionization energy of CHBr is thus derived to be < or = 9.17 +/- 0.23 eV. Literature values for DeltaH0f,298(CBr+) = 362.5 kcal mol(-1) and ionization energy of 10.43 eV for CBr are revised to be less than 332 kcal mol(-1) and 9.11 eV, respectively. Also based on a new experimental ionization energy, DeltaH0f,298(CH2Br2+) is revised to be 236.4 +/- 1.5 kcal mol(-1).
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Affiliation(s)
- Su-Yu Chiang
- National Synchrotron Radiation Research Center, 101, Hsin Ann Road, Science-Based Industrial Park Hsinchu 30077, Taiwan.
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Guan X, Du Y, Li YL, Kwok WM, Phillips DL. Comparison of the dehalogenation of polyhalomethanes and production of strong acids in aqueous and salt (NaCl) water environments: Ultraviolet photolysis of CH[sub 2]I[sub 2]. J Chem Phys 2004; 121:8399-409. [PMID: 15511161 DOI: 10.1063/1.1803508] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ultraviolet photolysis of CH(2)I(2) was studied in water and salt water solutions using photochemistry and picosecond time-resolved resonance Raman spectroscopy. Photolysis in both types of environments produces mainly CH(2)(OH)(2) and HI products. However, photolysis of CH(2)I(2) in salt water leads to the formation of different products/intermediates (CH(2)ICl and Cl(2) (-)) not observed in the absence of salt in aqueous solutions. The amount of CH(2)(OH)(2) and HI products appears to decrease after photolysis of CH(2)I(2) in salt water compared to pure water. We briefly discuss possible implications of these results for photolysis of CH(2)I(2) and other polyhalomethanes in sea water and other salt aqueous environments compared to nonsalt water solvated environments.
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Affiliation(s)
- Xiangguo Guan
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China
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Li YL, Zhao C, Kwok WM, Guan X, Zuo P, Phillips DL. Observation of a HI leaving group following ultraviolet photolysis of CH2I2 in water and anab initioinvestigation of the O–H insertion/HI elimination reactions of the CH2I–I isopolyhalomethane species with H2O and 2H2O. J Chem Phys 2003. [DOI: 10.1063/1.1595636] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kwok WM, Ma C, Parker AW, Phillips D, Towrie M, Matousek P, Phillips DL. Picosecond Time-Resolved Resonance Raman Study of CH2I−I Produced after Ultraviolet Photolysis of CH2I2 in CH3OH, CH3CN/H2O and CH3OH/H2O Solutions. J Phys Chem A 2003. [DOI: 10.1021/jp021611b] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Wai Ming Kwok
- Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2AY, U.K., Central Laser Facility, CLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K., and Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
| | - Chensheng Ma
- Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2AY, U.K., Central Laser Facility, CLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K., and Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
| | - Anthony W. Parker
- Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2AY, U.K., Central Laser Facility, CLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K., and Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
| | - David Phillips
- Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2AY, U.K., Central Laser Facility, CLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K., and Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
| | - Michael Towrie
- Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2AY, U.K., Central Laser Facility, CLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K., and Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
| | - Pavel Matousek
- Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2AY, U.K., Central Laser Facility, CLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K., and Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
| | - David Lee Phillips
- Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2AY, U.K., Central Laser Facility, CLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, U.K., and Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S. A. R., P. R. China
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18
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Li YL, Wang D, Phillips DL. Time-resolved resonance Raman spectroscopy and density functional theory investigation of the CH2I–I isomer and CH2I2⋯I molecular complex products produced from ultraviolet photolysis of CH2I2 in the solution phase: Comparison of the structure and chemical reactivity of polyhalomethane isomers and polyhalomethane–halogen atom molecular complexes. J Chem Phys 2002. [DOI: 10.1063/1.1511724] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Li YL, Zuo P, Lee Phillips D. Transient resonance Raman investigation of CHBr2 and CHBrCl radicals. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(02)01403-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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LI YUNLIANG, LEE CHEONGWAN, LEUNG KINGHUNG, HE GUOZHONG, PHILLIPS DAVIDLEE. Resonance Raman investigation of the short-time dynamics of the ultraviolet photodissociation of bromoform. Mol Phys 2002. [DOI: 10.1080/00268970210137329] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Li YL, Chen DM, Wang D, Phillips DL. Time-resolved resonance Raman and density functional theory investigation of iodocyclopropanation and addition reactions with alkenes after ultraviolet photolysis of iodoform. J Org Chem 2002; 67:4228-35. [PMID: 12054958 DOI: 10.1021/jo011163o] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A time-resolved resonance Raman spectroscopic investigation is reported for the ultraviolet photolysis of CHI(3) in pure cyclohexane and mixed cyclohexane/cyclohexene solvents. The ICHI-I species is observed in pure cyclohexane solvent. Upon addition of cyclohexene, the ICHI-I species lifetime is reduced and new bands from an I(2):cyclohexene complex are observed. Density functional theory computations show that ICHI-I and CHI(2) species have similar barriers of reaction toward addition to the C=C of ethylene. The addition reaction of ICHI-I with ethylene results in formation of an iodocyclopropane and I(2) molecule while addition of.CHI(2) results in initial formation of a diiodopropyl radical intermediate. Ultraviolet photolysis of CHI(3) in the presence of cyclohexene is known to produce a reasonable yield of iodonorcarane product and some addition reaction products. We present a mechanism for the iodocyclopropanation reaction that is consistent with both experimental and theoretical characterization of reaction intermediates formed after ultraviolet photolysis of CHI(3). We briefly discuss the concentration dependence of the time-resolved resonance Raman spectra and photochemistry in relation to the competition between the reaction of the ICHI-I and CHI(2) species with the C=C bond of olefins.
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Affiliation(s)
- Yun-Liang Li
- Department of Chemistry, University of Hong Kong, Pokfulam Road, SAR, People's Republic of China
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22
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Chan WS, Leung KH, Ong SY, Phillips DL. Transient Resonance Raman Investigation of 4-Iminocyclohexa-2,5-dienylidene and 4-Oxocyclohexa-2,5-dienylidene Carbenes in Aqueous Solution. J Phys Chem A 2002. [DOI: 10.1021/jp014254y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Wing Sum Chan
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R. China
| | - King Hung Leung
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R. China
| | - Shing Yau Ong
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R. China
| | - David Lee Phillips
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R. China
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23
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Li YL, Wang D, Phillips DL. Transient Resonance Raman Spectroscopy and Density Functional Theory Investigation of Iso-Dibromoacetic Acid Photoproduct Produced From Ultraviolet Photolysis of Dibromoacetic Acid in the Solution Phase. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2002. [DOI: 10.1246/bcsj.75.943] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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24
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Wang D, Li YL, Ho WS, Leung KH, Phillips DL. Transient resonance Raman and density functional theory investigation of the chlorine atom/carbon disulfide molecular complex involved in selective alkane photochlorination reactions. J Org Chem 2002; 67:747-52. [PMID: 11856015 DOI: 10.1021/jo0107195] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure and bonding of the chlorine atom/carbon disulfide (CS(2)/Cl) complex involved in selective photochlorination reactions with alkanes was directly probed using transient resonance Raman spectroscopy. The experimental Raman vibrational frequencies were compared to those computed from density functional theory calculations for probable structures of the CS(2)/Cl complex. Our results indicate that the S [double bond] C [double bond] S...Cl complex species is responsible for the approximately 370 nm transient absorption band observed after ultraviolet photolysis of CCl(4) in the presence of CS(2). We discuss the structure and properties of the S [double bond] C [double bond] S...Cl complex and compare them with those for the related benzene/Cl and pyridine/Cl complexes.
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Affiliation(s)
- Dongqi Wang
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong SAR, People's Republic of China
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25
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Wang D, Phillips DL, Fang WH. Density functional theory investigation of the reactions of CH2Br–I, CH2I–Br, CH2Cl–I, and CH2I–Cl isopolyhalomethanes with ethylene. Phys Chem Chem Phys 2002. [DOI: 10.1039/b204898c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Li YL, Wang D, Leung KH, Phillips DL. Transient Resonance Raman Investigation of the ∼570 nm Transient Absorption Band Observed after Ultraviolet Photolysis of Diiodomethane in the Solution Phase. J Phys Chem A 2001. [DOI: 10.1021/jp012608f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yun-Liang Li
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R. China
| | - Dongqi Wang
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R. China
| | - King Hung Leung
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R. China
| | - David Lee Phillips
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R. China
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27
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Transient resonance Raman and density functional theory investigation of the ultraviolet photolysis of dibromoacetonitrile in the solution phase. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)01279-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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28
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Li YL, Lee Phillips D. Transient resonance Raman and density functional theory investigation of CH3I–I produced from ultraviolet photolysis of iodomethane in the solution phase. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)01197-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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29
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Zheng X, Lee CW, Li YL, Fang WH, Phillips DL. Transient resonance Raman spectroscopy and density functional theory investigation of iso-CHBr2Cl and iso-CCl3Br photoproducts produced following ultraviolet excitation of CHBr2Cl and CCl3Br. J Chem Phys 2001. [DOI: 10.1063/1.1367391] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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Kwok WM, Ma C, Parker AW, Phillips D, Towrie M, Matousek P, Zheng X, Phillips DL. Picosecond time-resolved resonance Raman observation of the iso-CH2Cl–I and iso-CH2I–Cl photoproducts from the “photoisomerization” reactions of CH2ICl in the solution phase. J Chem Phys 2001. [DOI: 10.1063/1.1362178] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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