Mesogenic cyclopentadienyl cyclopalladated azobenzene complexes

The novel coordinatively saturated cyclopentadienyl palladium complexes [PdL(n)(eta(5)-C5H5)] (HL(n) = 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 degrees C.