Nematic and smectic mesophases in a new series of Cu(II) metallorganic complexes. II

Abstract

The synthesis and phase behaviour of a set of copper, bis-[N-[[4-[4-(tetrade-cyloxy)benzoyloxy],2-hydroxyphenyl]methylene]-alkanimino] complexes (referred to as 14-mNCu where m = 2–14 is the number of carbon atoms in the alkanamino group) is reported. With the single exception of the complex formed with the ethanamine, they show liquid crystal properties, either nematic only (m = 3–9) or smectic only (m = 15) or both of them (m = 10–14). Smectic mesomorphism is of the C type in all cases. The smectic interlayer spacing has been measured for compounds with m = 14 and 15 by X-ray diffraction. For both compounds it is significantly shorter than that found previously for m = 1. This should indicate that, in spite of the smectic phase homology, some substantial change in the molecular packing has occurred. Most compounds exhibit solid phase polymorphism, which is discussed briefly.