Correlation Times and Quadrupole Coupling Constants in Liquid N-Methylformamide and N-Methylacetamide

摘要

Longitudinal ~H, ~13C and ~15N nmr relaxation rates were measured in the liquid phase for N-methylformamide (NMP) over the temperature range 228-328 K and for N-methylacetamide (NMA) over the range 300-378 K. Rotational correlation times were determined for the formyl C-H and the N-H bonds. The motion of both mole- Cules is anisotopic, particularly that of N-methylacetamide. The activation energies are 5.6 kJ/mol for C-H and 19.7 kJ/mol for N-H in NMF and 20.4-22.5 kJ/mol for N-H in NMA.