Rigid-chain metallomesogenic polymers containing vanadyl or copper(II) ions coordinated in the main chain

Rigid-chain metallomesogenic polymers containing Cu(II) or VO(II) were prepared and characterized. All the polymers were soluble and melted without decomposition. They showed a thermotropic liquid-crystal (LC) behavior, and the mesophases were invariably preserved for a long time at room temperature in a metastable condition, with respect to the semicrystalline state. The nature of the mesophases of the Cu(II)-containing polymers was similar to that observed in analogous organic rigid-chain polymers having long lateral alkyl chains packed as extended ribbons. The VO(II)-containing polymers showed an LC polymorphism involving a smectic A and a nematic phase. For all the polymers in a smectic or smecticlike state at room temperature, X-ray diffraction data suggested short mean distances among the metal ions arranged in layers. (C) 2001 John Wiley & Sons, Inc.