Characterization of the first mixed-valent liquid-crystalline materials. Synthesis and structural properties of new binuclear ruthenium carboxylates

Abstract
The syntheses and structural properties of new binuclear ruthenium (II, III) complexes with long chain carboxylates, of general formula Ru2(RCO2)4X (R = C8H17, C11H23 and X = C1, RCOO), are reported. The thermodynamic behaviour of these compounds is strongly influenced by the nature of the counterion X. The chloro complexes (X = CI) are not mesomorphic whereas the carboxylato species (X = RCOO) are shown to exhibit a thermotropic columnar mesophase, thus providing the first example of a mixed-valent liquid-crystalline material.