Mesogenic cyclopentadienyl cyclopalladated azobenzene complexes

Abstract

The novel coordinatively saturated cyclopentadienyl palladium complexes [PdLⁿ(η⁵-C₅H₅)](HLⁿ= thermotropic 4-R,4′-R′-azobenzene; n= 1, R = R′= C₆H₁₃; n= 2, R = R′= C₆H₁₃O; n= 3, R = C₆H₁₃O, R′= C₈H₁₇OC₆H₄CO₂; n= 4, R = C₁₀H₂₁O, R′= C₈H₁₇OC₆H₄CO₂) are dark red solids which melt into isotropic fluids for n= 1,2, whereas for n= 3,4 liquid crystalline properties are exhibited with a stabilization of melting and clearing temperatures as high as 70 °C.