Complexes of 3d metal ions of the Schiff-base, 4-hydroxy-N '-(4 '-octadecyloxybenzylidene)benzohydrazide: Synthesis, spectral studies, crystal structure and magnetic interactions

摘要

A novel hydrazide-based mesogenic (nematic) Schiff-base, 4-hydroxy-N'-(4'-octadecyloxybenzylidene)benzohydrazide, (Hhodbbh) (abbreviated as HL3). Was prepared and its structure studied by elemental analyses, mass, NMR and IR spectra and single crystal XRD (triclinic space group P (1) over bar with Z = 2) techniques. The Schiff-base behaves as a non-deprotonated bi-dentate species in its metal complexes of the general formula, [M(HL3)(2)](OAc)(2) [M = Mn, Co, Ni, Cu and Zn]. The IR and NMR spectral data imply bonding of HL3 species through amidic oxygen and azomethine nitrogen atoms. The Mn-II and Co-II complexes show gradual decrease in the chi T-M product with lowering of temperature and negative Weiss constants characteristic of anti-ferromagnetic interaction. The Mn-II complex shows magnetic hysteresis loops at 2.0