Dipole Moments of 2,3-Dihalogeno-2,3-dimethylbutanes

Abstract

The dipole moments of 2,3-dichloro- and 2,3-dibromo-dimethylbutane were measured in carbon tetrachloride solution in the temperature range from −25° to +55°C, and in benzene solutions at 25°C. The moment was found to increase with temperature in carbon tetrachloride solution. Much higher values of moment were observed in benzene solutions. It was concluded from these experimental results that there exist two rotational isomers, the trans isomer with vanishing or a small moment, and the gauche isomer with a finite moment. The experimental result could be explained satisfactorily by the rotational isomer theory, but not on the assumption of only one potential trough at the trans position.