Synthesis and spectral studies of the mesogenic Schiff-base, N,N′-di-(4′-pentyloxybenzoate) salicylidene-1,8-diamino-3,6-dioxaoctane and crystal structure of the Zn(II) complex

A novel Schiff-base, N,N′-di-(4′-pentyloxybenzoate)salicylidene-1,8-diamino-3,6-dioxaoctane (H2L4) with the mesogenic phase, nematic droplets, was prepared and its structure studied by mass, NMR and IR spectra. The Schiff base reacts with Zn(II) as a di-negative tetra-dentate species, giving rise to a non-mesogenic tetrahedral complex, [ZnL4]. The complex crystallizes in monoclinic P21/n which possesses screw axis and n-glide and also inherent twofold axis by the combination of these two symmetry operations. Considerable torsion has been observed between benzoate ring and salicylaldimine ring on either side of the metal atom.