抄録
The temperature dependences of the frequencies and the widths of absorption lines of pure nuclear quadrupole resonances in hexachloroethane were studied. The change of resonance frequencies with temperature was explained as influences both of a torsional vibration of one end of CCl3 groups with respect to the other end and of a rotational vibration of those groups as a whole around the C–C axis, the frequency of the latter vibration being changed with temperature owing to a thermal expansion of the lattice. The line widths at half-maximum intensity were about 2 Kc/s at temperatures of 77°K and 90°K, and about 10 Kc/s at 196°K, although no absorption was detected at room temperature. The broadening of the resonance spectrum seems to be explainable by a reorientational motion around the C–C axis with much lower frequency than the resonance one.
