Relaxation of the CH2 Stretching Modes of Liquid Dihalomethanes

Abstract

The vibrational relaxation of the liquid dihalomethanes CH2I2, CH2Br2 and CH2Cl2 has been studied by a com- bination of IR/IR and IR/Raman pump-probe techniques applying a time resolution of ~2 ps. Careful analysis of the re- sults shows a general trend of decreasing relaxation rates from dichloromethane to diiodomethane, with few individual deviations. Possible explanations for these observations are discussed.