NUCLEAR-MAGNETIC-RESONANCE STUDY OF PROTON RELAXATION IN LIQUID FORMAMIDE, AND OF ITS INTERMOLECULAR STRUCTURE

Proton magnetic relaxation rates of pure formamide have been measured. The various contributions to the proton relaxation have been obtained and identified by isotopic H/D-substitution down to proton contents of only 1%, together with temperature dependent measurements at 15-degrees-C and 25-degrees-C. The relaxation rates in the measured temperature interval are dominated by magnetic dipole-dipole interactions between the protons, and additionally between the amide protons and the nitrogen N-14. Suppositions in literature of other mechanisms of relaxation have not been confirmed. The obtained relaxation rates have been related to intermolecular proton distances. The results are compared with other investigations of the intermolecular structure of formamide and are in reasonable agreement with expectation.