STRUCTURE-MESOPHASE RELATIONSHIPS IN DIALDEHYDE AND RELATED COMPLEXESOF COPPER(II) AND OXOVANADIUM(IV)

Copper(II) and oxovanadium(IV) complexes of a new series of alpha-subs tituted-dialdehydes have been synthesised, and their mesophase propert ies studied. Bis(4-alkyloxyphenylmalonaldehyde)copper and bis(4-alkylp henylmalonaldehyde)copper complexes show a narrow (10 degrees C) nemat ic phase below their clearing temperatures. The oxovanadium(IV) comple x of a ligand generally has a lower melting point than its copper anal ogue, but often does not show the liquid crystal phase shown by the co pper analogue. Introduction of a single methyl group in place of an al dehyde proton is sufficient to destroy liquid crystal properties.