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.
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.
Tang
Kuo-Chun
KC
Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, Michigan 48109-1055, USA.
Peng
Jian
J
Spears
Kenneth G
KG
Sension
Roseanne J
RJ
D006846:Hydrocarbons, Halogenated / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D010777:Photochemistry; D017785:Photons; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
D006846:Hydrocarbons, Halogenated; D012996:Solutions; C521928:bromoiodomethane; D008697:Methane