Nuclear magnetic resonance in toluene, toluene-αd3and toluene-d5

Abstract
Relaxation time studies are reported of toluene and the isotopic derivatives, toluene-αd3 and toluene-d5, between 20 K and their melting points. Mechanisms controlling the relaxation process, including the role of methyl group tunnelling at low temperatures, are discussed and restricting barrier heights calculated.