1H Spin–lattice relaxation times of quaternary piperidinium salts

Abstract

Spin–lattice relaxation times of the N-methyl protons of quaternary piperidinium salts, as well as piperidine bases as references, were measured in various solvents and for various concentrations. These relaxation times reflect overall molecular rotation rather than internal rotation of the methyl groups. Furthermore, the results are related to the dissociation equilibrium of the quaternary salts, and the dissociation equilibrium constants (K) were determined in some solvents.