Molecular Association of Methanol Vapor

Abstract

The absorption of infrared radiation by methanol vapor in the region 3200 to 3800 cm-1 has been studied at 305° and 335°K as a function of vapor density. The results best correlate with the model that methanol vapor is composed of monomer, dimer, and tetramer, with little or no trimer present. The heat of dissociation of the dimer is found to be approximately 3 kcal/mole, and that of the tetramer approximately 17 kcal/mole. The greater stability of the tetramer compared to the dimer is consistent with a cyclic structure for the tetramer.