A MATRIX INFRARED STUDY OF MONOMERIC FORMAMIDE

Article abstract of DOI:10.1016/0022-2860(83)85022-4

Infrared spectra of formamide have been recorded between 4000 and 200 cm^-1 in Ar, Kr, Xe, N2, and CO matrices.The fundamentals of monomeric formamide are assigned, the assignment of the low-frequency bands differing from the presented previously.The spectra of the deuterated species DCONH2, HCOND2 and DCOND2 in Ar matrices were also recorded and the fundamentals are assigned. "Complexation" of formamide with CO or N2 is found to shift the NH2 rocking and torsional bands in particular.The complexation of formamide with nitrogen, especially its influence on the NH2 torsional band, has been studied with the aid of ab initio 4-31G calculations.Three of the lowest energy configurations of the 1:1 complexes are presented.In rare-gas matrices, two overtone bands of the very intense torsional band have been found and these indicate only a very slight mechanical anharmonicity in this motion.The large difference between the torsional frequencies of the deuterated compounds HCONHD and HCONDH is discussed.