A Novel Series of Heteropolynuclear Metallomesogens: Organopalladium Complexes with Ferrocenophane‐Containing Ligands

Ferrocenophane-containing (Fcph) Schiff's bases p-C 12 H 25 O-(C 6 H 4 )CH=N(C 6 H 4 )Fcph (L A H) and p-C 12 H 25 O(C 6 H 4 )COO-(C 6 H 4 )CH=N(C 6 H 4 )Fcph (L B H) react with palladium(II) acetate to form μ-acetato- and chloro-bridged dimeric organopalladium complexes. By exchanging acetato-groups with the chloride anions, μ-chloro-bridged heteropolynuclear dimers are obtained that show thermotropic smectic A phases over a temperature range of 198 to 260 °C. The complexes [PdCIL A ] 2 and [PdCΙL B ] 2 can be transformed into a variety of mixed-ligand Pd ΙΙ complexes by treatment with salicyl-aldimine p-C 12 H 25 O(C 6 H 4 )COO(C6H3)(OH)CH=N(C6H4)-Fcph (L C H) and β-aminovinyl ketone p-C 12 H 25 O(C 6 H 4 )-COCH=CHNH(C 6 H 4 )Fcph (L D H). The obtained mixed-ligand heterometallic complexes [PdL A L C ], [PdL B L C ], [PdL A L D ] and [PdL B L D ] exhibit enantiotropic, thermotropic nematic phases over a broad temperature range from 71 to 205 °C. The structures of the synthesized compounds were characterized by means of 1 H NMR, IR and UV spectroscopy, as well as elemental analysis. The liquid crystalline properties were studied by polarising optical microscopy and DSC.