Ligational aspects of some 4f metal complexes of a mesogenic Schiffbase, N,N’- di-(4-dodecyloxysalicylidene)-1’,3’-diaminopropane: Synthesis and spectral studies

Abstract

A liquid crystalline (smectic-F and smectic-A phases)Schiff base, N,N′-di-(4-dodecyloxysalicylidene)-1′,3′-diaminopropane(abbreviated as H₂L) and a series of lanthanide (III) complexes of the type [Ln₂(LH₂)₃(NO₃)₄](NO₃)₂, (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Ho) have been synthesized and characterized by elemental analysis, mass spectrometry, FTIR, and UV-Vis spectral techniques. The IR spectral data imply bidentate chelation of the Schiff base in its zwitterionic form (as LH₂) to the Ln^III ions through two phenolate oxygens, rendering the overall geometry of the complexes possibly to distorted mono-capped octahedra. The optical and thermal behavior studies (POM & DSC techniques) reveal that despite H₂L being mesogenic, none of the Ln^III complexes synthesized under this study exhibits mesomorphism. Fluorescence studies show emissions of H₂L and Sm^III complexx.