The synthesis, characterization and mesomorphic properties of copper(II), palladium(II), vanadyl(IV) and iron(III) chloride complexes derived from salicylaldimine structures are reported. The copper and palladium complexes exhibited smectic A phases, however vanadyl and iron chloride complexes showed crystalline phase. The palladium complexes have lower melting and clearing points, and a wider temperature range of mesophase. This lowering in clearing points between M=Pd and M=Cu analogues was attributed to the weaker core-core interaction between palladium centres within layers in the mesophase. The crystal and molecular structures of bis [N-(3-hydroxypropyl)-4-octanoylsalicylaldiminato] copper(II) were determined by means of X-ray analysis. This complex crystallizes in the monoclinic space group p2(1)/c, with a = 5.4908(23)Angstrom b = 19.847(5)Angstrom, c = 16.636(4)Angstrom, beta = 96.87(3)degrees, and Z = 2. The intramolecular separation of Cu-Cu atoms is 3.022(3)Angstrom. The structure shows that the molecular shape is nearly hat with two copper atoms lying 0.067(4)Angstrom above and below the plane of N1, O1a, O1 and O2 atoms.
