The liquid-crystalline and luminescence properties of polycatenar diphenylpyridine complexes of Palladium(II)

Abstract

Palladium complexes of polycatenar 2,5-diphenylpyridine ligands were prepared in a two-stage reaction from (NH4)2[PdCl4]; their liquid crystal and emission properties are reported and discussed. For tetracatenar and hexacatenar derivatives, neither the ligand nor their complexes were liquid crystalline. The tricatenar ligand only showed a SmC phase identified by a Schlieren texture. Palladation of the tricatenar and dicatenar ligands led to complexes showing a SmA phase, with a range that depended on the ligand. The identity of the mesophases was supported by small angle X-ray scattering (SAXS). All ligands and complexes exhibited luminescence properties with the emission lifetimes of the complexes suggesting the absence of phosphorescence.