Lanthanide iodide and perchlorate complexes of 4-N-(2'-hydroxybenzylidine)aminoantipyrine

Eighteen new complexes of lanthanide iodides and perchlorates with 4-N-(2'-hydroxybenzylidene)aminoantipyrine (HBAAP) have been prepared and characterized. They have the general formulae, [Ln(HBAAP)5I]I2, where Ln=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Y, and [Ln(HBAAP)n](ClO4)3, where n=4 for La, Pr and Nd, and n=5 for Sm, Gd, Tb, Dy, Ho and Y. Conductance studies indicate 1:2 electrolytic behaviour for the iodide complexes and 1:3 electrolytic behaviour for the perchlorate complexes. The magnetic moments of all the complexes agree well with Van Vleck values. Their infrared spectra reveal that HBAAP acts as a bidentate neutral ligand, one of the iodides is coordinated and none of the perchlorates is coordinated. Electronic spectra of the Nd complexes show weak covalency in the lanthanide-ligand bond. Thermogravimetric studies of the complexes indicate that these complexes are stable upto 200deg and undergo complete decomposition in the range 200 - 620deg forming the respective stable lanthanide oxides. (author)