1
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Nimmrich A, Panman MR, Berntsson O, Biasin E, Niebling S, Petersson J, Hoernke M, Björling A, Gustavsson E, van Driel TB, Dohn AO, Laursen M, Zederkof DB, Tono K, Katayama T, Owada S, Nielsen MM, Davidsson J, Uhlig J, Hub JS, Haldrup K, Westenhoff S. Solvent-Dependent Structural Dynamics in the Ultrafast Photodissociation Reaction of Triiodide Observed with Time-Resolved X-ray Solution Scattering. J Am Chem Soc 2023. [PMID: 37163700 PMCID: PMC10375522 DOI: 10.1021/jacs.3c00484] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Resolving the structural dynamics of bond breaking, bond formation, and solvation is required for a deeper understanding of solution-phase chemical reactions. In this work, we investigate the photodissociation of triiodide in four solvents using femtosecond time-resolved X-ray solution scattering following 400 nm photoexcitation. Structural analysis of the scattering data resolves the solvent-dependent structural evolution during the bond cleavage, internal rearrangements, solvent-cage escape, and bond reformation in real time. The nature and structure of the reaction intermediates during the recombination are determined, elucidating the full mechanism of photodissociation and recombination on ultrafast time scales. We resolve the structure of the precursor state for recombination as a geminate pair. Further, we determine the size of the solvent cages from the refined structures of the radical pair. The observed structural dynamics present a comprehensive picture of the solvent influence on structure and dynamics of dissociation reactions.
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Affiliation(s)
- Amke Nimmrich
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Matthijs R Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Oskar Berntsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Elisa Biasin
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Stephan Niebling
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Jonas Petersson
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Maria Hoernke
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Alexander Björling
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Emil Gustavsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Tim B van Driel
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Asmus O Dohn
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
- Faculty of Physical Sciences, University of Iceland, VR-III, 107 Reykjavík, Iceland
| | - Mads Laursen
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Diana B Zederkof
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Tetsuo Katayama
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Shigeki Owada
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Martin M Nielsen
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Jan Davidsson
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Jens Uhlig
- Department of Chemical Physics, Lund University, Box 124, 22100 Lund, Sweden
| | - Jochen S Hub
- Georg-August-Universität Göttingen, Institute for Microbiology and Genetics, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Kristoffer Haldrup
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
- Department of Chemical Physics, Lund University, Box 124, 22100 Lund, Sweden
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2
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Pal D, Agrawal SK, Chakraborty A, Chakraborty S. IR spectra of CH2I2 in Ar and N2 cryomatrices: Evidence of unusual band splitting in N2 matrix. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.132853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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3
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Choi EH, Lee Y, Heo J, Ihee H. Reaction dynamics studied via femtosecond X-ray liquidography at X-ray free-electron lasers. Chem Sci 2022; 13:8457-8490. [PMID: 35974755 PMCID: PMC9337737 DOI: 10.1039/d2sc00502f] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 06/06/2022] [Indexed: 02/04/2023] Open
Abstract
X-ray free-electron lasers (XFELs) provide femtosecond X-ray pulses suitable for pump–probe time-resolved studies with a femtosecond time resolution. Since the advent of the first XFEL in 2009, recent years have witnessed a great number of applications with various pump–probe techniques at XFELs. Among these, time-resolved X-ray liquidography (TRXL) is a powerful method for visualizing structural dynamics in the liquid solution phase. Here, we classify various chemical and biological molecular systems studied via femtosecond TRXL (fs-TRXL) at XFELs, depending on the focus of the studied process, into (i) bond cleavage and formation, (ii) charge distribution and electron transfer, (iii) orientational dynamics, (iv) solvation dynamics, (v) coherent nuclear wavepacket dynamics, and (vi) protein structural dynamics, and provide a brief review on each category. We also lay out a plausible roadmap for future fs-TRXL studies for areas that have not been explored yet. Femtosecond X-ray liquidography using X-ray free-electron lasers (XFELs) visualizes various aspects of reaction dynamics.![]()
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Affiliation(s)
- Eun Hyuk Choi
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Yunbeom Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Jun Heo
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Hyotcherl Ihee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- Center for Advanced Reaction Dynamics, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
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4
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Filming ultrafast roaming-mediated isomerization of bismuth triiodide in solution. Nat Commun 2021; 12:4732. [PMID: 34354075 PMCID: PMC8342516 DOI: 10.1038/s41467-021-25070-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022] Open
Abstract
Roaming reaction, defined as a reaction yielding products via reorientational motion in the long-range region (3 - 8 Å) of the potential, is a relatively recently proposed reaction pathway and is now regarded as a universal mechanism that can explain the unimolecular dissociation and isomerization of various molecules. The structural movements of the partially dissociated fragments originating from the frustrated bond fission at the onset of roaming, however, have been explored mostly via theoretical simulations and rarely observed experimentally. Here, we report an investigation of the structural dynamics during a roaming-mediated isomerization reaction of bismuth triiodide (BiI3) in acetonitrile solution using femtosecond time-resolved x-ray liquidography. Structural analysis of the data visualizes the atomic movements during the roaming-mediated isomerization process including the opening of the Bi-Ib-Ic angle and the closing of Ia-Bi-Ib-Ic dihedral angle, each by ~40°, as well as the shortening of the Ib···Ic distance, following the frustrated bond fission.
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5
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Kim H, Kim JG, Kim TW, Lee SJ, Nozawa S, Adachi SI, Yoon K, Kim J, Ihee H. Ultrafast structural dynamics of in-cage isomerization of diiodomethane in solution. Chem Sci 2020; 12:2114-2120. [PMID: 34163975 PMCID: PMC8179290 DOI: 10.1039/d0sc05108j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Despite extensive studies on the isomer species formed by photodissociation of haloalkanes in solution, the molecular structure of the precursor of the isomer, which is often assumed to be a vibrationally hot isomer formed from the radical pair, and its in-cage isomerization mechanism remain elusive. Here, the structural dynamics of CH2I2 upon 267 nm photoexcitation in methanol were probed with femtosecond X-ray solution scattering at an X-ray free-electron laser. The determined molecular structure of the transiently formed species that converts to the CH2I–I isomer has the I–I distance of 4.17 Å, which is longer than that of the isomer (3.15 Å) by more than 1.0 Å and the mean-squared displacement of 0.45 Å2, which is about 100 times larger than those of typical regular chemical bonds. These unusual structural characteristics are consistent with either a vibrationally hot form of the CH2I–I isomer or the loosely-bound radical pair (CH2I˙⋯I˙). The structural dynamics of in-cage isomerization of CH2I2 and the unusual structure of the loosely-bound isomer precursor were unveiled with femtosecond X-ray liquidography (solution scattering).![]()
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Affiliation(s)
- Hanui Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea .,KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea.,Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| | - Jong Goo Kim
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| | - Tae Wu Kim
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| | - Sang Jin Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea .,KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea.,Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| | - Shunsuke Nozawa
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK) Tsukuba Ibaraki 305-0801 Japan.,Department of Materials Structure Science, School of High Energy Accelerator Science, The Graduate University for Advanced Studies Tsukuba Ibaraki 305-0801 Japan
| | - Shin-Ichi Adachi
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK) Tsukuba Ibaraki 305-0801 Japan.,Department of Materials Structure Science, School of High Energy Accelerator Science, The Graduate University for Advanced Studies Tsukuba Ibaraki 305-0801 Japan
| | - Kihwan Yoon
- Department of Chemistry, The Catholic University of Korea Bucheon 14662 Republic of Korea
| | - Joonghan Kim
- Department of Chemistry, The Catholic University of Korea Bucheon 14662 Republic of Korea
| | - Hyotcherl Ihee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea .,KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea.,Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
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6
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Panman MR, Biasin E, Berntsson O, Hermann M, Niebling S, Hughes AJ, Kübel J, Atkovska K, Gustavsson E, Nimmrich A, Dohn AO, Laursen M, Zederkof DB, Honarfar A, Tono K, Katayama T, Owada S, van Driel TB, Kjaer K, Nielsen MM, Davidsson J, Uhlig J, Haldrup K, Hub JS, Westenhoff S. Observing the Structural Evolution in the Photodissociation of Diiodomethane with Femtosecond Solution X-Ray Scattering. PHYSICAL REVIEW LETTERS 2020; 125:226001. [PMID: 33315438 DOI: 10.1103/physrevlett.125.226001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/25/2020] [Accepted: 10/19/2020] [Indexed: 06/12/2023]
Abstract
Resolving the structural dynamics of the initial steps of chemical reactions is challenging. We report the femtosecond time-resolved wide-angle x-ray scattering of the photodissociation of diiodomethane in cyclohexane. The data reveal with structural detail how the molecule dissociates into radicals, how the radicals collide with the solvent, and how they form the photoisomer. We extract how translational and rotational kinetic energy is dispersed into the solvent. We also find that 85% of the primary radical pairs are confined to their original solvent cage and discuss how this influences the downstream recombination reactions.
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Affiliation(s)
- Matthijs R Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Elisa Biasin
- Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Oskar Berntsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Markus Hermann
- Georg-August-Universität Göttingen, Institute for Microbiology and Genetics, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Stephan Niebling
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Ashley J Hughes
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Joachim Kübel
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Kalina Atkovska
- Georg-August-Universität Göttingen, Institute for Microbiology and Genetics, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Emil Gustavsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Amke Nimmrich
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Asmus O Dohn
- Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Mads Laursen
- Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Diana B Zederkof
- Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Alireza Honarfar
- Department of Chemical Physics, Lund University, Box 124, S-2210, Lund, Sweden
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Tetsuo Katayama
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Shigeki Owada
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Tim B van Driel
- LCLS, SLAC National Laboratory, Menlo Park, California 94025, USA
| | - Kasper Kjaer
- LCLS, SLAC National Laboratory, Menlo Park, California 94025, USA
| | - Martin M Nielsen
- Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Jan Davidsson
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, SE75120 Uppsala, Sweden
| | - Jens Uhlig
- Department of Chemical Physics, Lund University, Box 124, S-2210, Lund, Sweden
| | - Kristoffer Haldrup
- Centre for Molecular Movies, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Jochen S Hub
- Georg-August-Universität Göttingen, Institute for Microbiology and Genetics, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
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7
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Leshchev D, Khakhulin D, Newby G, Ki H, Ihee H, Wulff M. Sub-nanosecond secondary geminate recombination in mercury halides HgX 2 (X = I, Br) investigated by time-resolved x-ray scattering. J Chem Phys 2019. [DOI: 10.1063/1.5096422] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Denis Leshchev
- European Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38000 Grenoble, France
| | | | - Gemma Newby
- European Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Hosung Ki
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 305-701, South Korea
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea
| | - Hyotcherl Ihee
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon 305-701, South Korea
- Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea
| | - Michael Wulff
- European Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38000 Grenoble, France
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8
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Time-resolved photoacoustic calorimetry of organometallic ligand substitution in alkane solvents: Molybdenum-alkane σ bond controls fast ligand addition to molybdenum pentacarbonyl. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.01.018] [Citation(s) in RCA: 2] [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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9
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Borin VA, Matveev SM, Budkina DS, El-Khoury PZ, Tarnovsky AN. Direct photoisomerization of CH 2I 2vs. CHBr 3 in the gas phase: a joint 50 fs experimental and multireference resonance-theoretical study. Phys Chem Chem Phys 2018; 18:28883-28892. [PMID: 27722308 DOI: 10.1039/c6cp05129d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Femtosecond transient absorption measurements powered by 40 fs laser pulses reveal that ultrafast isomerization takes place upon S1 excitation of both CH2I2 and CHBr3 in the gas phase. The photochemical conversion process is direct and intramolecular, i.e., it proceeds without caging media that have long been implicated in the photo-induced isomerization of polyhalogenated alkanes in condensed phases. Using multistate complete active space second order perturbation theory (MS-CASPT2) calculations, we investigate the structure of the photochemical reaction paths connecting the photoexcited species to their corresponding isomeric forms. Unconstrained minimum energy paths computed starting from the S1 Franck-Condon points lead to S1/S0 conical intersections, which directly connect the parent CHBr3 and CH2I2 molecules to their isomeric forms. Changes in the chemical bonding picture along the S1/S0 isomerization reaction path are described using multireference average coupled pair functional (MRACPF) calculations in conjunction with natural resonance theory (NRT) analysis. These calculations reveal a complex interplay between covalent, radical, ylidic, and ion-pair dominant resonance structures throughout the nonadiabatic photochemical isomerization processes described in this work.
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Affiliation(s)
- Veniamin A Borin
- Center for Photochemical Sciences, Department of Chemistry, Bowling Green State University, Bowling Green, Ohio, USA.
| | - Sergey M Matveev
- Center for Photochemical Sciences, Department of Chemistry, Bowling Green State University, Bowling Green, Ohio, USA.
| | - Darya S Budkina
- Center for Photochemical Sciences, Department of Chemistry, Bowling Green State University, Bowling Green, Ohio, USA.
| | - Patrick Z El-Khoury
- Physical Sciences Division, Pacific Northwest National Laboratory, P. O. Box 999, Richland, WA 99352, USA
| | - Alexander N Tarnovsky
- Center for Photochemical Sciences, Department of Chemistry, Bowling Green State University, Bowling Green, Ohio, USA.
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10
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Ehn A, Bood J, Li Z, Berrocal E, Aldén M, Kristensson E. FRAME: femtosecond videography for atomic and molecular dynamics. LIGHT, SCIENCE & APPLICATIONS 2017; 6:e17045. [PMID: 30167293 PMCID: PMC6062331 DOI: 10.1038/lsa.2017.45] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 03/02/2017] [Accepted: 03/10/2017] [Indexed: 05/18/2023]
Abstract
Many important scientific questions in physics, chemistry and biology require effective methodologies to spectroscopically probe ultrafast intra- and inter-atomic/molecular dynamics. However, current methods that extend into the femtosecond regime are capable of only point measurements or single-snapshot visualizations and thus lack the capability to perform ultrafast spectroscopic videography of dynamic single events. Here we present a laser-probe-based method that enables two-dimensional videography at ultrafast timescales (femtosecond and shorter) of single, non-repetitive events. The method is based on superimposing a structural code onto the illumination to encrypt a single event, which is then deciphered in a post-processing step. This coding strategy enables laser probing with arbitrary wavelengths/bandwidths to collect signals with indiscriminate spectral information, thus allowing for ultrafast videography with full spectroscopic capability. To demonstrate the high temporal resolution of our method, we present videography of light propagation with record high 200 femtosecond temporal resolution. The method is widely applicable for studying a multitude of dynamical processes in physics, chemistry and biology over a wide range of time scales. Because the minimum frame separation (temporal resolution) is dictated by only the laser pulse duration, attosecond-laser technology may further increase video rates by several orders of magnitude.
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Affiliation(s)
- Andreas Ehn
- Division of Combustion Physics, Department of Physics, Lund University, Lund SE-223 63, Sweden
| | - Joakim Bood
- Division of Combustion Physics, Department of Physics, Lund University, Lund SE-223 63, Sweden
| | - Zheming Li
- Division of Combustion Physics, Department of Physics, Lund University, Lund SE-223 63, Sweden
| | - Edouard Berrocal
- Division of Combustion Physics, Department of Physics, Lund University, Lund SE-223 63, Sweden
| | - Marcus Aldén
- Division of Combustion Physics, Department of Physics, Lund University, Lund SE-223 63, Sweden
| | - Elias Kristensson
- Division of Combustion Physics, Department of Physics, Lund University, Lund SE-223 63, Sweden
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11
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Mereshchenko AS, Butaeva EV, Borin VA, Eyzips A, Tarnovsky AN. Roaming-mediated ultrafast isomerization of geminal tri-bromides in the gas and liquid phases. Nat Chem 2015; 7:562-8. [DOI: 10.1038/nchem.2278] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 05/09/2015] [Indexed: 11/09/2022]
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12
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Caplins BW, Lomont JP, Nguyen SC, Harris CB. Vibrational Cooling Dynamics of a [FeFe]-Hydrogenase Mimic Probed by Time-Resolved Infrared Spectroscopy. J Phys Chem A 2014; 118:11529-40. [DOI: 10.1021/jp510517z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Benjamin W. Caplins
- Department
of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Justin P. Lomont
- Department
of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Son C. Nguyen
- Department
of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Charles B. Harris
- Department
of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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13
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Reid SA. When isomerisation is electron transfer: the intriguing story of the iso-halocarbons. INT REV PHYS CHEM 2014. [DOI: 10.1080/0144235x.2014.942548] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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14
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Duke CB, Letterman RG, Johnson JO, Barr JW, Hu S, Ross CR, Webster CE, Burkey TJ. Photochemistry of Chromium Arene Tricarbonyl Complexes with Tethered Pyridinyl and Propenyl Groups: Investigations of the Effect of Ring Size on Chelate Formation, Structure, and Linkage Isomerization. Organometallics 2014. [DOI: 10.1021/om400928k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Charles B. Duke
- Department of Chemistry, The University of Memphis, 213 Smith
Chemistry Building, Memphis, Tennessee 38152-3550, United States
| | - Roger G. Letterman
- Department of Chemistry, The University of Memphis, 213 Smith
Chemistry Building, Memphis, Tennessee 38152-3550, United States
| | - Jermaine O. Johnson
- Department of Chemistry, The University of Memphis, 213 Smith
Chemistry Building, Memphis, Tennessee 38152-3550, United States
| | - James W. Barr
- Department of Chemistry, The University of Memphis, 213 Smith
Chemistry Building, Memphis, Tennessee 38152-3550, United States
| | - Songnan Hu
- Department of Chemistry, The University of Memphis, 213 Smith
Chemistry Building, Memphis, Tennessee 38152-3550, United States
| | - Charles R. Ross
- Department of Structural
Biology, St. Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105-2794, United States
| | - Charles Edwin Webster
- Department of Chemistry, The University of Memphis, 213 Smith
Chemistry Building, Memphis, Tennessee 38152-3550, United States
| | - Theodore J. Burkey
- Department of Chemistry, The University of Memphis, 213 Smith
Chemistry Building, Memphis, Tennessee 38152-3550, United States
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15
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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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16
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Heilweil EJ, Johnson JO, Mosley KL, Lubet PP, Webster CE, Burkey TJ. Engineering Femtosecond Organometallic Chemistry: Photochemistry and Dynamics of Ultrafast Chelation of Cyclopentadienylmanganese Tricarbonyl Derivatives with Pendant Benzenecarbonyl and Pyridinecarbonyl Groups. Organometallics 2011. [DOI: 10.1021/om2003656] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Edwin J. Heilweil
- Optical Technology Division, Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8443, United States
| | - Jermaine O. Johnson
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Karen L. Mosley
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Philippe P. Lubet
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Charles Edwin Webster
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Theodore J. Burkey
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
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17
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Gittermann SM, Letterman RG, Jiao T, Leu GL, DeYonker NJ, Webster CE, Burkey TJ. Bond Energies, Reaction Volumes, and Kinetics for σ- and π-Complexes of Mo(CO)5L. J Phys Chem A 2011; 115:9004-13. [DOI: 10.1021/jp203915q] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shannon M. Gittermann
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Roger G. Letterman
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Tianjie Jiao
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Ging-Long Leu
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Nathan J. DeYonker
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Charles Edwin Webster
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
| | - Theodore J. Burkey
- Department of Chemistry, The University of Memphis, Memphis, Tennessee 38152-3550, United States
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18
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Buchachenko A, Halberstadt N, Lepetit B, Roncero O. Ar ··· I 2 : A model system for complex dynamics. INT REV PHYS CHEM 2010. [DOI: 10.1080/0144235031000075726] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Alexei Buchachenko
- a Laboratory of Molecular Structure and Quantum Mechanics, Department of Chemistry , Moscow State University , Moscow , 119992 , Russia
| | - Nadine Halberstadt
- b LPQT-IRSAMC , Université Paul Sabatier and CNRS , 118 route de Narbonne, Toulouse , 31062 , France
| | - Bruno Lepetit
- c LCAR-IRSAMC , Université Paul Sabatier and CNRS , 118 route de Narbonne, Toulouse , 31062 , France
| | - Octavio Roncero
- d Instituto de Matemáticas y Física Fundamental , CSIC , Serrano 123, Madrid , 28006 , Spain
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19
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To TT, Heilweil EJ, Duke CB, Ruddick KR, Webster CE, Burkey TJ. Development of Ultrafast Photochromic Organometallics and Photoinduced Linkage Isomerization of Arene Chromium Carbonyl Derivatives. J Phys Chem A 2009; 113:2666-76. [DOI: 10.1021/jp8068909] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Chapter 1 Multireference and Spin–Orbit Calculations on Photodissociations of Hydrocarbon Halides. ADVANCES IN QUANTUM CHEMISTRY 2009. [DOI: 10.1016/s0065-3276(08)00401-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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21
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Saitow KI, Naitoh Y, Tominaga K, Yoshihara K. Photodissociation of CH2I2 and subsequent electron transfer in solution. Chem Asian J 2008; 3:696-709. [PMID: 18381663 DOI: 10.1002/asia.200700351] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We studied photoinduced reactions of diiodomethane (CH(2)I(2)) upon excitation at 268 nm in acetonitrile and hexane by subpicosecond-nanosecond transient absorption spectroscopy. The transient spectra involve two absorption bands centered at around 400 (intense) and 540 nm (weak). The transients probed over the range 340-740 nm show common time profiles consisting of a fast rise (<200 fs), a fast decay ( approximately 500 fs), and a slow rise. The two fast components were independent of solute concentration, whereas the slow rise became faster (7-50 ps) when the concentration in both solutions was increased. We assigned the fast components to the generation of a CH(2)I radical by direct dissociation of the photoexcited CH(2)I(2) and its disappearance by subsequent primary geminate recombination. The concentration-dependent slow rise produced the absorption bands centered at 400 and 540 nm. The former consists of different time-dependent bands at 385 and 430 nm. The band near 430 nm grew first and was assigned to a charge-transfer (CT) complex, CH(2)I(2) (delta+)I(delta-), formed by a photofragment I atom and the solute CH(2)I(2) molecule. The CT complex is followed by full electron transfer, which then develops the band of the ion pair CH(2)I(2) (+)I(-) at 385 nm on the picosecond timescale. On the nanosecond scale, I(3) (-) was generated after decay of the ion pair. The reaction scheme and kinetics were elucidated by the time-resolved absorption spectra and the reaction rate equations. We ascribed concentration-dependent dynamics to the CT-complex formation in pre-existing aggregates of CH(2)I(2) and analyzed how solutes are aggregated at a given bulk concentration by evaluating a relative local concentration. Whereas the local concentration in hexane monotonically increased as a function of the bulk concentration, that in acetonitrile gradually became saturated. The number of CH(2)I(2) molecules that can participate in CT-complex formation has an upper limit that depends on the size of aggregation or spatial restriction in the neighboring region of the initially photoexcited CH(2)I(2). Such conditions were achieved at lower concentrations in acetonitrile than in hexane.
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Affiliation(s)
- Ken-Ichi Saitow
- The Graduate University for Advanced Studies, Myodaiji, Okazaki 444-8585, Japan.
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22
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23
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Time-Resolved X-Ray Diffraction from Liquids. ADVANCES IN CHEMICAL PHYSICS 2008. [DOI: 10.1002/9780470238080.ch1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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24
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Oelkers AB, Schutte EJ, Tyler DR. Solvent cage effects: the influence of radical mass and volume on the recombination dynamics of radical cage pairs generated by photolysis of [CpCH2CH2N(CH3)C(O)(CH2)nCH3Mo(CO)3]2(n = 3, 8, 13, 18) (Cp = η5-C5H4) complexes. Photochem Photobiol Sci 2008; 7:228-34. [DOI: 10.1039/b709005f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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25
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Petersen C, Thøgersen J, Knak Jensen S, Keiding SR, Sassi P. Solvent response to solute photo-dissociation. Phys Chem Chem Phys 2008; 10:990-5. [DOI: 10.1039/b711466d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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To TT, Heilweil EJ, Duke CB, Burkey TJ. Solvent and Structural Effects on Ultrafast Chelation Dynamics of Arene Chromium Tricarbonyl Sulfide Derivatives. J Phys Chem A 2007; 111:6933-7. [PMID: 17628047 DOI: 10.1021/jp071172m] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The chelation dynamics of three new [Cr{eta6-C6H5C(O)R}(CO)3] complexes, 1 [R = CH2(SCH3)], 2 [R = CH(SCH3)2], and 3 [R = C(SCH3)3], has been investigated on the picosecond to millisecond time scales by UV pump/IR probe transient absorption spectroscopy following photodissociation of CO in room temperature n-heptane, tetrahydrofuran (THF), and acetonitrile. In n-heptane, UV irradiation of 1, 2, or 3 dissociates CO to initially yield a Cr-S chelate (in which the pendant sulfide moiety is coordinated to the metal center) and a transient Cr-heptane solvate in approximately 1:2, 1:2, and 2:1 ratios, respectively. The Cr-heptane solvate is unstable and converts to the Cr-S chelate within 30 ns in each case. Irradiation of 2 or 3 in THF yields both the Cr-S chelate and Cr-THF solvate in approximately 1:3 and 1:1 ratios, respectively. The Cr-THF solvate converts to the Cr-S chelate on the second or longer time scale. All three complexes appear to yield the Cr-NCCH3 solvate exclusively within 50 ps following irradiation in acetonitrile. The solvent effect on chelation is in striking contrast to that previously reported for the analogous RCpMn(CO)3 derivatives, 4-6. In acetonitrile, only chelation is observed for the Mn series and only solvent coordination is observed for the Cr series, but in heptane both chelation and solvent coordination are observed in both series.
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Affiliation(s)
- Tung T To
- Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8443, USA
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27
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Guan X, Lin X, Kwok WM, Du Y, Li YL, Zhao C, Wang D, Phillips DL. Ultraviolet photolysis of CH2I2 in methanol: O-H insertion and HI elimination reactions to form a dimethoxymethane product. J Phys Chem A 2007; 109:1247-56. [PMID: 16833436 DOI: 10.1021/jp046060z] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ultraviolet photolysis of low concentrations of CH2I2 in methanol solution found that CH2I2 is converted into dimethoxymethane and some H+ and I- products. Picosecond time-resolved resonance Raman (ps-TR3) experiments observed that the isodiiodomethane (CH2I-I) photoproduct decayed faster as the concentration of methanol increases, suggesting that isodiiodomethane is reacting with methanol. Ab initio calculations indicate isodiiodomethane is able to react with methanol via an O-H insertion/HI elimination to form an iodoether (ICH2-O-CH3) and HI products. The iodoether can then further react via another O-H insertion/HI elimination reaction to form the dimethoxymethane (CH3-O-CH2-O-CH3) observed in the photochemistry experiments. A reaction mechanism consistent with these experimental and theoretical observations is proposed.
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Affiliation(s)
- Xiangguo Guan
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, PRC
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28
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Oelkers AB, Scatena LF, Tyler DR. Femtosecond Pump−Probe Transient Absorption Study of the Photolysis of [Cp‘Mo(CO)3]2 (Cp‘ = η5-C5H4CH3): Role of Translational and Rotational Diffusion in the Radical Cage Effect. J Phys Chem A 2007; 111:5353-60. [PMID: 17552498 DOI: 10.1021/jp064849z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Femtosecond pump-probe studies of the photodissociation and subsequent radical cage pair recombination dynamics of the organometallic dimer [Cp'Mo(CO)3]2 (Cp' = eta5-C5H4CH3) are reported. The dynamics following photodissociation were studied in numerous noncoordinating hydrocarbon solvents. The results indicate that primary geminate recombination occurs on an ultrafast time scale (tau approximately 5 ps) and the efficiency of cage escape is inversely proportional to solvent viscosity. Investigation of the time-dependent anisotropy in this system allowed for an estimate of the rotational correlation time of the radical fragments (tau approximately 5-25 ps). Comparison of the rates of rotational motion with the population kinetics shows that the primary solvent cage dynamics and recombination efficiency are controlled by radical diffusion and not by radical rotation.
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Affiliation(s)
- Alan B Oelkers
- Department of Chemistry, University of Oregon, Eugene, OR 97403, USA
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29
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Liu YJ, De Vico L, Lindh R, Fang WH. Spin-Orbit Ab Initio Investigation of the Ultraviolet Photolysis of Diiodomethane. Chemphyschem 2007; 8:890-8. [PMID: 17352002 DOI: 10.1002/cphc.200600737] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The UV photodissociation (<5 eV) of diiodomethane (CH(2)I(2)) is investigated by spin-orbit ab initio calculations. The experimentally observed photodissociation channels in the gas and condensed phases are clearly assigned by multi-state second-order multiconfigurational perturbation theory in conjunction with spin-orbit interaction through complete active space-state interaction potential energy curves. The calculated results indicate that the fast dissociations of the first two singlet states of CH(2)I(2) and CH(2)I--I lead to geminate-radical products, CH(2)I (.)+I((2)P(3/2)) or CH(2)I (.)+ I*((2)P(1/2)). The recombination process from CH(2)I--I to CH(2)I(2) is explained by an isomerization process and a secondary photodissociation reaction of CH(2)I--I. Finally, the study reveals that spin-orbits effects are significant in the quantitative analysis of the electronic spectrum of the CH(2)I--I species.
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Affiliation(s)
- Ya-Jun Liu
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.
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30
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Bixon M, Jortner J. Electron Transfer-from Isolated Molecules to Biomolecules. ADVANCES IN CHEMICAL PHYSICS 2007. [DOI: 10.1002/9780470141656.ch3] [Citation(s) in RCA: 232] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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31
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Herrmann H. On the photolysis of simple anions and neutral molecules as sources of O−/OH, SOx−and Cl in aqueous solution. Phys Chem Chem Phys 2007; 9:3935-64. [PMID: 17646883 DOI: 10.1039/b618565g] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This contribution examines the aqueous phase photolysis processes of simple anions such as nitrate, nitrite, peroxodisulfate and neutral molecules such as H2O2. The review includes new results on absolute effective quantum yields for the photodissociation processes of NO3(-), NO2(-), S2O8(2-), HSO5(-), S2O6(2-), HOCl, and chloroacetone in an aqueous solution. The quantum yields for the photolysis of nitrate and nitrite have also been determined as a function of temperature. Models to interpret the wavelength and the temperature dependencies of the quantum yields for the different systems are discussed and a simple model treatment is developed to quantify the effects of (i) impulse conservation, (ii) electrostatic interaction (e.g., ion-dipole, dipole-dipole and coulomb interaction between the photofragments directly after photolytic fragmentation), and (iii) diffusion and recombination. The combined impulse-interaction-diffusion (IID) model is compared to the experimentally observed effective radical formation quantum yields and reasonable agreement is found for a number of systems. It is shown that the temperature dependencies for effective quantum yields of photolysis processes in aqueous solution are not only governed by the temperature dependence of the viscosity of water but also determined by the temperature dependence of the rate constants of the photofragment recombination reactions.
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Affiliation(s)
- Hartmut Herrmann
- Leibniz-Institut für Troposphärenforschung, D-04318, Leipzig, Germany.
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32
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Savitsky A, Paul H, Shushin A. Initial Radical Separation after Photolysis of 2,2′-Azobis(isobutyronitrile) (AIBN) in Solution: Modeling the Primary Cage Effect for Polar Radicals. Helv Chim Acta 2006. [DOI: 10.1002/hlca.200690231] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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33
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Li YL, Zuo P, Phillips DL. A Density Functional Theory Study of the Reactions of Dichlorocarbene and Isodichloromethane with H2O. MOLECULAR SIMULATION 2006. [DOI: 10.1080/0892702031000152109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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34
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Polyansky DE, Danilov EO, Voskresensky SV, Rodgers MAJ, Neckers DC. Photodecomposition of Peroxides Containing a 1,4-Bis(phenylethynyl)benzene Chromophore. J Phys Chem A 2006; 110:4969-78. [PMID: 16610814 DOI: 10.1021/jp055078m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photodecomposition dynamics of 1,4-bis(2-[4-tert-butylperoxycarbonylphenyl]ethynyl)benzene (1) have been compared with those of model compounds in the picosecond and nanosecond time domains by various photophysical techniques. Ultrafast visible transient absorption spectrometry revealed the singlet excited state of 1,4-bis(4-phenylethynyl)benzene (BPB) depopulates radiatively with a rate of 1.75 x 10(9) s(-1) and 95% efficiency. Phenyl ester moieties attached to the BPB core accelerate intersystem crossing (k = 2.8 x 10(8) s(-1)) and reduce the fluorescence quantum yield (phi(FL) = 0.82). The peroxide oxygen-oxygen bond of 1 cleaves (k = 3.6 x 10(11) s(-1)) directly from the singlet excited state (60% efficiency) causing a highly reduced fluorescence yield and leading to formation of aroyloxyl radicals. The next reaction step involves decarboxylation of the aroyloxyl radicals. Transient absorption signals in the MID IR region correspond to CO2 with the formation rate (2.5 x 10(6) s(-1)) as measured by nanosecond transient IR experiments. The transient IR spectra of the excited state of BPB, as well as of the aroyloxyl radical, evidenced a red shift in the acetylene triple bond absorption indicative of a decrease in the bond order. This clearly shows that delocalization of excitation energy over the BPB chromophore induces significant structural changes. The proposed mechanism is based on the rates of photophysical and photochemical channels and involves an additional population channel of the BPB triplet excited state from the upper singlet states.
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Affiliation(s)
- Dmitry E Polyansky
- Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA
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35
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Grimm C, Kandratsenka A, Wagener P, Zerbs J, Schroeder J. Photoinduced Isomerization Kinetics of Diiodomethane in Supercritical Fluid Solution: Local Density Effects. J Phys Chem A 2006; 110:3320-9. [PMID: 16509658 DOI: 10.1021/jp055608e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The density dependence of diiodomethane photoinduced isomerization in supercritical (sc) CO2, CHF3, and C2H6 was investigated by transient absorption spectroscopy, covering a fluid density range from 0.7 to 2.5 (in reduced units). The solvent-caged photoproduct iso-diiodomethane is formed even at the lowest density, and its yield increases about 4-fold over the whole range. At the same time, isomer formation rate constants increase by roughly an order of magnitude and show little variation between CO2, C2H6, and CHF3. Furthermore, the formation rate constant decreases significantly with increasing excitation energy. We propose an isomer formation mechanism involving a rapidly established preequilibrium between a solvent-caged iodine atom-methyliodide radical pair and a loosely bound iodine-methyliodide radical complex, from which the reaction subsequently proceeds to the isomer. The latter step seems to be controlled by collisional stabilization of the initially hot radical moiety, as the formation rate constant increases linearly with sc solvent viscosity. The model predicts a quadratic dependence of relative isomer yield on fluid density. A corresponding correlation is found with the local fluid density, calculated via solute-solvent radial distribution functions obtained from molecular dynamics (MD) simulations.
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Affiliation(s)
- Christian Grimm
- Institut für Physikalische Chemie, Universität Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany
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36
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Lenzer T, Oum K, Schroeder J, Sekiguchi K. Gas-Phase Collisional Relaxation of the CH2I Radical after UV Photolysis of CH2I2. J Phys Chem A 2005; 109:10824-31. [PMID: 16331925 DOI: 10.1021/jp053686w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transient UV absorption spectra and kinetics of the CH(2)I radical in the gas phase have been investigated at 313 K. Following laser photolysis of 1-3 mbar CH(2)I(2) at 308 nm, transient spectra in the wavelength range 330-390 nm were measured at delay times between 60 ns and a few microseconds. The change of the absorption spectra at early times was attributed to vibrational cooling of highly excited CH(2)I radicals by collisional energy transfer to CH(2)I(2) molecules. From transient absorption decays measured at specific wavelengths, time-dependent concentrations of vibrationally "hot" and "cold" CH(2)I and CH(2)I(2) were extracted by kinetic modeling. In addition, the transient absorption spectrum of CH(2)I radicals between 330 and 400 nm was reconstructed from the simulated concentration-time profiles. The evolution of the absorption spectra of CH(2)I radicals and CH(2)I(2) due to collisional energy transfer was simulated in the framework of a modified Sulzer-Wieland model. Additional master equation simulations for the collisional deactivation of CH(2)I by CH(2)I(2) yield DeltaE values in reasonable agreement with earlier direct studies on the collisional relaxation of other systems. In addition, the simulations show that the shape of the vibrational population distribution of the hot CH(2)I radicals has no influence on the measured UV absorption signals. The implications of our results with respect to spectral assignments in recent ultrafast spectrokinetic studies of the photolysis of CH(2)I(2) in dense fluids are discussed.
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Affiliation(s)
- Thomas Lenzer
- Institut für Physikalische Chemie, Universität Göttingen, Tammannstrasse 6, D-37077 Göttingen, Germany
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Du Y, Guan X, Kwok WM, Chu LM, Phillips DL. Comparison of the Dehalogenation of Dihalomethanes (CH2XI, where X = Cl, Br, I) Following Ultraviolet Photolysis in Aqueous and NaCl Saltwater Environments. J Phys Chem A 2005; 109:5872-82. [PMID: 16833922 DOI: 10.1021/jp0504928] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ultraviolet photolysis of low concentrations of CH(2)XI (X = Cl, Br, I) were investigated in water and saltwater solutions by photochemistry and picosecond time-resolved resonance Raman spectroscopy. Photolysis in both kinds of solutions formed mostly CH(2)(OH)(2) and HI and HX products. However, photolysis of the CH(2)XI molecules in saltwater resulted in production of some CH(2)XCl products not observed in aqueous solutions without salt present. The appearance of these new products in saltwater solutions is accompanied by a decrease in the amount of CH(2)(OH)(2), HI, and HX products compared to photolysis in aqueous solutions without salt present. The possible implications for photolysis of CH(2)XI and other polyhalomethanes in seawater and other salt aqueous environments compared to nonsaltwater solvated environments is briefly discussed.
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Affiliation(s)
- Yong Du
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P.R. China
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38
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Lin X, Zhao C, Phillips DL. Anab initiostudy of the reactions of CH2X-X (X=Cl, Br, I) isopolyhalomethanes with nCH3OH. MOLECULAR SIMULATION 2005. [DOI: 10.1080/08927020412331337050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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39
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Odelius M, Kadi M, Davidsson J, Tarnovsky AN. Photodissociation of diiodomethane in acetonitrile solution and fragment recombination into iso-diiodomethane studied with ab initio molecular dynamics simulations. J Chem Phys 2004; 121:2208-14. [PMID: 15260775 DOI: 10.1063/1.1768171] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Photodissociation of diiodomethane (CH2I2) in acetonitrile solution has been studied with ab initio molecular dynamics simulations, which show how the iso-diiodomethane photoproduct (CH2I-I) can be formed. The first excited state, described by the "restricted open-shell Kohn-Sham" density functional method, is dissociative and photoexcitation of diiodomethane induces a breaking of one of the C-I bonds. In the simulations, we observe that energy dissipation to the surrounding solvent is essential in the formation of a stable iso-diiodomethane molecule. The caging effect of the solvent results in a recombination of the CH2I and I fragments into iso-diiodomethane on a picosecond time scale. The molecular dynamics simulations enable us to study the cage effect as well as the relaxation of intermediates and the distribution of energy. The CH2I fragment is formed vibrationally excited along the C-I stretching mode. After recombination of the CH2I and I fragments, iso-diiodomethane shows a strong vibration excitation in the CH2 group, which could be used as a fingerprint of the proposed mechanism.
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Affiliation(s)
- Michael Odelius
- Department of Physics, AlbaNova, Stockholm University, S-106 91, Sweden.
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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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41
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Yeston JS, To TT, Burkey TJ, Heilweil EJ. Ultrafast Chelation Dynamics of Cyclopentadienyl Manganese Tricarbonyl Derivatives with Pendant Sulfides. J Phys Chem B 2004. [DOI: 10.1021/jp031219d] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jake S. Yeston
- Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8443 and Department of Chemistry, Campus Box 526060, University of Memphis, Memphis, Tennessee 38152-6060
| | - Tung T. To
- Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8443 and Department of Chemistry, Campus Box 526060, University of Memphis, Memphis, Tennessee 38152-6060
| | - Theodore J. Burkey
- Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8443 and Department of Chemistry, Campus Box 526060, University of Memphis, Memphis, Tennessee 38152-6060
| | - Edwin J. Heilweil
- Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8443 and Department of Chemistry, Campus Box 526060, University of Memphis, Memphis, Tennessee 38152-6060
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42
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Monson E, Kopelman R. Nonclassical kinetics of an elementary A+B-->C reaction-diffusion system showing effects of a speckled initial reactant distribution and eventual self-segregation: experiments. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:021103. [PMID: 14995423 DOI: 10.1103/physreve.69.021103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2003] [Indexed: 05/24/2023]
Abstract
We demonstrate here the implementation of an experimental system suitable for the study of the diffusion limited A+B-->0, nonclassical reaction behavior. Using a combination of a fluorescent calcium indicator and a calcium ion which is initially "caged," a pulse of near-UV light initiates the reaction which is followed as product formation vs time. Sensitive dependence on the initial reactant distribution is observed through patterns in the uncaging UV light profile. In one case, the reaction progress passes through two nonclassical time regimes, one due to roughness originating from laser speckles, followed by one consistent with the three-dimensional Zeldovich rate of (1/rho(A)-1/rho(A0)) approximately t(3/4), with features matching Monte Carlo simulations on this initial distribution. This behavior is contrasted with reactions initiated by a homogeneous source which induces random initial reactant distributions, though both systems seem to approach the asymptotic limit of self-segregation of reactants.
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Affiliation(s)
- Eric Monson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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43
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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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44
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Tarnovsky AN, Sundström V, Åkesson E, Pascher T. Photochemistry of Diiodomethane in Solution Studied by Femtosecond and Nanosecond Laser Photolysis. Formation and Dark Reactions of the CH2I−I Isomer Photoproduct and Its Role in Cyclopropanation of Olefins. J Phys Chem A 2003. [DOI: 10.1021/jp035406n] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander N. Tarnovsky
- Contribution from the Department of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Villy Sundström
- Contribution from the Department of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Eva Åkesson
- Contribution from the Department of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Torbjörn Pascher
- Contribution from the Department of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
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45
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Grimm C, Kling M, Schroeder J, Troe J, Zerbs J, Schroeder J, Troe J. Density-dependent photochemical branching ratio in supercritical CO2: Photodissociation and isomerization of diiodomethane. Isr J Chem 2003. [DOI: 10.1560/d8hj-jqtw-w43y-qf1g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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46
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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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47
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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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48
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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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49
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Steinhurst DA, Baronavski AP, Owrutsky JC. Transient infrared spectroscopy of Mn2(CO)10 with 400 nm excitation. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(02)00994-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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50
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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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