Rotational isomerism in methyl formate and methyl acetate; a low-temperature matrix infrared study using thermal molecular beams

Abstract

IR spectra of methyl formate and methyl acetate have been studied by trapping thermal molecular beams in Ar matrices. For methyl formate, four bands have been assigned to the anti conformer. Δ H o (anti-syn) for the conformational equilibrium is 4750 ± 190 cal mol −1. In methyl acetate there is an increase in Δ H o due to steric hindrance between the methyl groups.