Temperature-controlled kinetics of the growth and relaxation of alcohol clusters in an argon matrix

Abstract

The clustering processes of monohydric alcohols (from methanol to hexanol) were investigated by FTIR spectroscopy using the isolation in an argon matrix technique. The transformation of the FTIR bands of the free O–H groups (3600–3800 cm−1) into diffuse bands (3000–3600 cm−1), which were assigned to the stretching vibrations of the H-bonded O–H groups in various clusters, was monitored in its initial stage during softening of the matrices by heating from 20 to 50 K. Band-shape analysis was carried out for the investigated systems. The magnitude of the inhomogeneous broadening due to the matrix effect was evaluated from the bandwidth of the monomer species. The H-bond dissociation times in matrices were evaluated from the cluster bandwidths. These data correlate with those measured directly in ultra-fast infrared experiments of alcohols in solution.