Picosecond time-resolved resonance Raman observation of the iso-CH_2Cl-I and iso-CH_2I-Cl photoproducts from the 'photoisomerization' reactions of CH_2ICl in the solution phase

摘要

We report a preliminary picosecond Stokes time-resolved resonance Raman investigation of the initial formation and subsequent decay of the photoproduct produced following 267 nm excitation of CH2CII in acetonitrile solution. Density-functional theory computations were done for several probable photoproduct species. Comparison of these computational results and results from a recent femtosecond transient absorption study to our present picosecond resonance Raman spectra indicate that the iso-CH2Cl—I species is mainly produced and associated with the —460 nm transient absorption band. The iso-CH2Cl—I species appears to decay and form appreciable amounts of the more stable iso-CH2I--Cl species that is associated with a approx 370 nm transient absorption band after a few hundred ps.