Synthesis and physicochemical studies of the chloride and bromide complexes of yttrium and lanthanides with 4-N-(4'-antipyryl-methylidene)aminoantipyrine

摘要

Twenty new complexes of chlorides and bromides of yttrium and lanthanides with the Schiff base 4-N"(4'-antipyrylmethylidene)aminoantipyrine (AA) have been prepared and characterised. They have the general formula, [Ln(AA)_2Cl_3] and [Ln(AA)_2Br_2]Br where Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho and Er, Molar conductance studies indicate slight dissociation for the chloride complexes and 1:1 electrolytic behaviour for the bromide complexes. The magnetic moments of all the complexes agree well with VanVleck values. The infrared spectra reveal that AA functions as a terdentate ligand in all these complexes coordinating through the oxygens of both the carbonyl groups and the azomethine nitrogen. Electronic spectra of Nd, Ho and Er for the chloride complexes and that of Pr, Nd, Ho and Er for the bromide complexes show weak covalency in the metal-ligand bond.