1H NMR Studies of Motions in Solid (CH3)3CBr, (CH3)3CCl, and (CH3)3CNO2: Methyl Group and t-Butyl Group Uniaxial Reorientations

Abstract

Abstract 1H NMR line shapes and their second moments for t-butyl compounds {(CH3)3CX where X=Br, Cl, and NO2} have been studied as a function of temperature. It is shown that the methyl group and the t-butyl group uniaxial reorientations are distinguished by 1H NMR technique. The dipolar interactions modulated by these motions are reported in three cases: the first where methyl reorientation is fast while t-butyl reorientation is slow, the second where t-butyl reorientation is faster than methyl reorientation, and the third where both reorientations are in almost the same rate. The results obtained here are consistent with the results of 1H NMR relaxation studies reported previously.