Temperature dependence of spin-relaxation times of protons in liquids

Abstract

Temperature dependences of the spin–lattice and the spin–spin relaxation times of protons in 1,1,2,2-tetrabromoethane(CHBr₂CHBr₂), ethylene glycol(OHCH₂CH₂OH) and trichloroethene (HCClCCl₂) were investigated. The spin–lattice relaxation times of 1,1,2,2-tetrabromoethane and ethylene glycol exhibit minima at 229 and 227 K respectively. Theoretical calculations are made by assuming that dipolar interactions between the H—Br, H—H and the H—Cl nuclei in the compounds show good agreement with the experimental results. In 1,1,2,2,-tetrabromoethane and ethylene glycol only the rotational motions of molecules lead to spin-relaxation; however, in trichloroethene both the rotational and translational motions are effective.