Gas and solution phase chloroiodomethane short-time photodissociation dynamics in the B-band absorption

Resonance Raman spectra were obtained within and to the red of the B-band absorption spectrum of gas phase chloroiodomethane and chloroiodomethane in cyclohexane solvent. The spectra show the fundamental and overtones of the nominal C-I stretch (nν5) and combination bands of the CH2wag (ν3), I-C-C1 bend (ν6), and the CH2scissor (ν2) fundamentals with the C-I stretch bands (nν5). The chloroiodomethane B-band short-time photodissociation dynamics have significant substituent effects relative to the B-band of iodomethane due to the presence of the C-C1 chromophore n(X) → σ * (C-X) transitions ≈ 170 nm that are close to the B-band absorption of chloroiodomethane but absent in iodomethane.