Crystal structure and ligational aspects of the mesogenic Schiff base, N,N′-di-(4-hexadecyloxysalicylidene)diaminoethane, with some rare earth metal ions

A mesogenic Schiff base, N,N′-di-(4-hexadecyloxysalicylidene)diaminoethane, H2dhdsde (abbreviated as H2L1) that exhibit smectic-C (SmC  ) mesophase, was synthesized and its structure studied by elemental analyses, mass, NMR & IR spectra and single crystal XRD (triclinic space group P1¯ with Z = 1) techniques. Bi-dentate bonding of the Schiff base in the mesogenic LaIII complex was implied on the basis of IR & NMR spectral data. As per the spectral studies of the complexes, the Zwitterionic species of the ligand (H2L1) coordinates to LnIII ion through two phenolate oxygens rendering the overall geometry around the metal ion to distorted square antiprism (Ln = La, Pr, Nd, Sm, Eu) and monocapped octahedron (Ln = Gd, Tb, Dy, Ho).

Graphical abstractA mesogenic Schiff base, N,N’-di-(4-hexadecyloxysalicylidene)diaminoethane, H2L1, exhibiting smectic-C (SmC  ) mesophase, crystallizes in triclinic space group (P1¯ with Z = 1) and coordinates to LnIII ions as a bidentate Zwitterionic species yielding both mesogenic and non-mesogenic complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide