Smectic bimetallomesogens: Synthesis, characterization and mesomorphic properties and the crystal structure of bis [N-(3-hydroxypropyl)-4-octanoylsalicylaldiminato] copper (II) complex

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 p2₁/c, with a = 5.4908 (23) Å b = 19.847(5) Å, c = 16.636(4) Å, β = 96.87 (3) , and Z = 2. The intramolecular separation of Cu Cu atoms is 3.022(3) Å. The structure shows that the molecular shape is nearly flat with two copper atoms lying 0.067(4) Å above and below the plane of N1, O1a, O1 and O2 atoms.