Raman bandshape analysis of <i>o</i>‐chlorobenzaldehyde: microviscosity‐dependent study

Abstract

Abstract Isotropic Raman bandshape analysis was carried out for the CO stretching mode of o ‐chlorobenzaldehyde using various polar and non‐polar solvents as a function of the solvents' hydrodynamic properties. The bandwidths of the isotropic components were measured at high dilution where the bandshape approaches Lorentzian. The effect of solvent viscosity on bandwidth was studied in details. It is clear that macroscopic consideration of the hydrodynamic force is not sufficient to correlate the vibrational relaxation rate (τ v −1 ) with the parameter f (ρ, η, n ), involving dynamic viscosity. The bandshape analysis was carried out taking the microviscosity into account using the parameter f m . The parameter f m shows a better correlation than f (ρ, η, n ). Copyright © 2004 John Wiley &amp; Sons, Ltd.