Transient resonance Raman investigation of the ∼570 nm transient absorption band observed after ultraviolet photolysis of diiodomethane in the solution phase

Abstract

We present transient resonance Raman experiments done to obtain a vibrational spectrum of the photoproduct species associated with the ∼570 nm transient absorption band observed after ultraviolet photolysis of CH 2I 2 in the solution phase. The experimental vibrational frequencies and their isotopic shifts are compared to results of density functional theory calculations for the probable photoproduct species. Our results show that both the CH 2I 2 + cation and iso-CH 2I-I species contribute to the transient ∼570 nm absorption band. relative amounts of CH 2I 2 + cation and iso-CH 2I-I species observed depend on the power of the 532 nm probe laser beam. We briefly discuss the qualitative properties of the visible electronic transitions of the CH 2I 2+ cation and iso-CH 2I-I species.