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Tang KC, Peng J, Spears KG, Sension RJ. Communications: Photoinitiated bond dissociation of bromoiodomethane in solution: Comparison of one-photon and two-photon excitations and the formation of iso-CH(2)Br-I and iso-CH(2)I-Br. J Chem Phys 2010; 132:141102. [PMID: 20405978 DOI: 10.1063/1.3374680] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Broadband UV-visible femtosecond transient absorption spectroscopy was used to monitor the excited state photochemistry of CH(2)BrI following one-photon excitation at 266 or 271 nm and two-photon excitation at 395 or 405 nm in 2-butanol. The results for one-photon excitation agree with earlier studies in acetonitrile, showing clear formation of iso-CH(2)Br-I following cleavage of the C-I bond. In contrast, two-photon excitation at 395 nm results in the appearance of a blueshifted photoproduct absorption band assigned to formation of iso-CH(2)I-Br following cleavage of the C-Br bond. The results are discussed in the context of prior experimental and theoretical work and the prospects for optical control of bond cleavage.
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Affiliation(s)
- Kuo-Chun Tang
- Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109-1055, USA
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Benjamin I. Theoretical Studies of Solute Vibrational Energy Relaxation at Liquid Interfaces. J Phys Chem B 2006; 110:9375-82. [PMID: 16686479 DOI: 10.1021/jp056420y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recent advances in the theoretical understanding of solute vibrational energy relaxation at liquid interfaces and surfaces are described. Non-equilibrium molecular dynamics simulations of the relaxation of an initially excited solute molecule are combined with equilibrium force autocorrelation calculations to gain insight into the factors that influence the vibrational relaxation rate. Diatomic and triatomic nonpolar, polar, and ionic solute molecules adsorbed at the liquid/vapor interface of several liquids as well as at the water/CCl(4) liquid/liquid interface are considered. In general, the vibrational relaxation rate is significantly slower (a factor of 3 to 4) at the liquid/vapor and liquid/liquid interface than in the bulk due to the reduced density, which gives rise to a reduced contribution of the repulsive solvent-solute forces on the vibrational mode. The surface effects on the ionic solutes are much smaller (50% or less slower relaxation relative to the bulk). This is due to the fact that ionic solutes at the interface are able to keep part of their solvation shell to a degree that depends on their size. Thus, a significant portion of the repulsive forces is maintained. A high degree of correlation is found between the peak height of the solvent-solute radial distribution function and the vibrational relaxation rate. The relaxation rate at the liquid/liquid interface strongly depends on the location of the solute across the interface and correlates with the change in the density and polarity profile of the interface.
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Affiliation(s)
- Ilan Benjamin
- Department of Chemistry and Biochemistry, University of California at Santa Cruz, Santa Cruz, CA 95064, USA
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Shiang JJ, Yoder LM, Sension RJ. Structure and Function in the Isolated Reaction-Center Complex of Photosystem II. 2. Models for Energy Relaxation and Charge Separation in a Protein Matrix. J Phys Chem B 2003. [DOI: 10.1021/jp021983k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joseph J. Shiang
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Laurie M. Yoder
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Roseanne J. Sension
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
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Pedersen DB, Weitz E. Photolysis of intrasilicalite I2: Spectroscopy and dynamics. J Chem Phys 2002. [DOI: 10.1063/1.1386488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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He Z, Gao G, Hand ES, Kispert LD, Strand A, Liaaen-Jensen S. Iodine-Catalyzed R/S Isomerization of Allenic Carotenoids. J Phys Chem A 2002. [DOI: 10.1021/jp013006z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhangfei He
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, and Organic Chemistry Laboratories, Faculty of Chemistry and Biology, Norwegian University of Science and Technology, Gløshaugen, N0-7491 Trondheim, Norway
| | - Guoqiang Gao
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, and Organic Chemistry Laboratories, Faculty of Chemistry and Biology, Norwegian University of Science and Technology, Gløshaugen, N0-7491 Trondheim, Norway
| | - Elli S. Hand
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, and Organic Chemistry Laboratories, Faculty of Chemistry and Biology, Norwegian University of Science and Technology, Gløshaugen, N0-7491 Trondheim, Norway
| | - Lowell D. Kispert
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, and Organic Chemistry Laboratories, Faculty of Chemistry and Biology, Norwegian University of Science and Technology, Gløshaugen, N0-7491 Trondheim, Norway
| | - Aase Strand
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, and Organic Chemistry Laboratories, Faculty of Chemistry and Biology, Norwegian University of Science and Technology, Gløshaugen, N0-7491 Trondheim, Norway
| | - Synnφve Liaaen-Jensen
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, and Organic Chemistry Laboratories, Faculty of Chemistry and Biology, Norwegian University of Science and Technology, Gløshaugen, N0-7491 Trondheim, Norway
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Terazima M. Energy Transfer from Photoexcited Electronic States to the Thermal Modes. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2001. [DOI: 10.1246/bcsj.74.595] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Terazima M. Vibrational relaxation from electronically photoexcited states in solution studied by the acoustic peak delay method: hydrogen bonding effect to betaine-30. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)00373-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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