Mesogenic lanthanoid metal complexes of a non-mesogenic Schiff-base, N,N′-di-(4-hexadecyloxysalicylidene)-l′,8′-diamino-3′,6′-dioxaoctane

A non-mesogenic Schiff-base, N,N′-di-(4-hexadecyloxysalicylidene)-l′,8′-diamino-3′,6′-dioxaoctane, H2dhdsdd (H2L2), was synthesized, structure studied by elemental analyses and mass, NMR and IR spectra and ligated to some LnIII metal ions that yielded mesogenic (SmA/N) LnIII complexes of the general composition, [Ln2(L2H2)3(NO3)4](NO3)2, where Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Ho. IR and NMR spectral data imply a bi-dentate bonding of the Schiff-base in its zwitterionic form (as L2H2) to the LnIII ions through two phenolate oxygens, rendering the overall geometry around LnIII to distorted mono-capped octahedron.