Synthesis, Structural Studies of Some Lanthanide Complexes of the Mesogenic Schiff-base, N,N’-di-(4’-octadecyloxybenzoate)salicylidene-l’’,3’’-diamino-2’’-propanol
World Journal of Pathology 2014, 3:6
A mesogenic Schiff-base, N,N’-di-(4’-octadecyloxybenzoate)salicylidene-l’’,3’’-diamino-2’’-propanol (H2L5) was synthesized and its structure studied by elemental analyses and mass, NMR and IR spectra and ligated to some LnIII metal ions that yielded mesogenic (N / SmA) LnIII complexes of the general composition, [Ln(L5H2)3(NO3)](NO3)2, where Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Ho. Among the metal complexes, only that of LaIII 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 L5H2) to the LnIII ions through two phenolate oxygens, rendering the overall geometry around LnIII to eight-coordinated polyhedron, possibly distorted Square Antiprism.
Mesogenic LnIII complexes, Zwiterionic, Distorted Square Antiprism, NMR & IR spectra.