METAL-CONTAINING HOMOPOLYMERS SHOWING A PARAMAGNETIC NEMATIC MESOPHASE

We have synthesized and characterized new homopolyesters containing paramagnetic units. Bis(N-R-4-hydroxysalicylaldiminato)copper(II) compounds (R = -CηH2n+i, η = 1, 5, and 10) were condensed with an acid dichloride in order to obtain the target polymers. Mesomorphic melts below the decomposition temperatures were observed except for η = 1. EPR and DSC measurements showed two different crystalline forms. In one of them, Cu2+ was in an environment close to a square-planar coordination. An isotropic EPR signal was observed and could be related to Cu-Cu or Cu-0 interactions among different metallomesogens in the neighborhood. These compounds gave evidence of some degradation under electric fields. © 1990, American Chemical Society. All rights reserved.