STUDY OF INTER-MOLECULAR HYDROGEN-BONDING IN FORMAMIDE BY VIBRATIONAL SPECTROSCOPY

Intermolecular hydrogen bonding in formamide has been studied by an analysis of the NH stretching regions in both the infrared and Raman spectra of solid and liquid formamide and for solutions of formamide in nitromethane and liquid sulphur dioxide. The spectra indicate that on melting the linked C2h dimers of the solid break up to form smaller units of linked dimers having Cs symmetry. In solution the dimeric structure is disrupted to the monomer form with increasing dilution. A simple valence force field calculation has also been carried out and indicates extensive mixing of the low frequency vibrations. © 1979.