Synthesis, Structural Studies of Some Lanthanide Complexes of the Mesogenic Schiff‐Base, N,N′ ‐di‐(4′‐Octadecyloxybenzoate)Salicylidene‐I″, 3″‐Diamino‐2″‐Propanol

Abstract

A mesogenic Schiff-base, N,N '-di-(4'-octyloxybenzoate)salicylidene-l'',3''-diamino-2''-propanol (H 2 L 5 ) was synthesized and its structure studied by elemental analyses and mass, NMR and IR spectra and ligated to some Ln III metal ions that yielded mesogenic (N / SmA) Ln III complexes of the general composition, [Ln(L 5 H 2 ) 3 (NO 3 )](NO 3 ) 2 , where Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Ho. Among the metal complexes, only that of La III is found to be mesogenic. with smectic-X and nematic phases. The IR and NMR spectral data imply a bi-dentate bonding of the Schiff-base in its zwitterionic form (as L 5 H 2 ) to the Ln III ions through two phenolate oxygens, rendering the overall geometry around Ln III to eight-coordinated polyhedron, possibly distorted Square Antiprism.