R. E. Gerkin, P. Szerenyi
Sep 1, 1971
Citations
0
Influential Citations
9
Citations
Journal
Journal of Chemical Physics
Abstract
Electron paramagnetic resonance absorption by phosphorescent triphenylene‐h12 and ‐d12 oriented in single crystals of symmetric dodecahydrotriphenylene has been investigated in the temperature range from 4 to 250°K. It has been shown that both guest molecules are multiply oriented in this host. In addition, two distinct kinds of mixed crystals have been identified on the basis of the zero‐field splittings manifested by the guest molecules. In one kind of mixed crystal, guest splittings were found to change with time until stable, fixed values were established. Since splitting differences are related to orientational differences, guest rearrangement in the solid host is implied, which has not heretofore been reported. The temperature dependence of at least one zero‐field splitting parameter D is complex in that its magnitude does not increase monotonically with decreasing temperature. The temperature dependences of the zero‐field splitting parameters E are even more complex. X‐ray diffraction data indicate...