NMR and EPR Studies of the Phase Transitions in the Discogen Bis [1,3-(p-n-Octyloxy-Phenyl) Propane-1,3 Dionato] Cu-(II)

ABSTRACTThe Crystal →discotic → isotropic phase transitions in the octyloxy-phenyl substituted Cu complex (C8O-Cu) has for the first time been studied from 1H NMR. The wide Lorentzian line in the discotic phase indicates a comparatively ordered structure with some degree of fluidity. However, the splitted lines in the isotropic phase results from disordering. C8O-Cu has an asymmetric central line (˜ 145 Oe) with a complex hyperfine structure (h. f. s.) in EPR. A blurring of h. f. s. occurs in the discotic phase and the weak set of h. f. lines disappear in the isotropic phase. These NMR and EPR results are in conformity with the lamellar structure proposed for C8O-Cu.