The synthesis and magnetic and spectral studies of some lanthanide(III) chelates of 6-methyl pyridine-2-aldoxime

A series of trivalent lanthanide chelates of the type [Ln(HMPOX)3(X)2](X) (where Ln3+ = La, Pr, Nd, Sm, Gd or Dy; HMPOX = 6-methylpyridine-2-aldoxime and X- = NO3 or Cl) have been synthesised by the direct reaction of 6-methylpyridine-2-aldoxime with lanthanide(III) nitrates or chlorides in 2,2'-dimethoxypropane and ethanol. These chelates have been characterized by analysis, molar conductance, X-ray powder diffraction patterns, magnetic, electronic and vibrational spectral studies. The analytical data reveal the presence of 1:3 (metal:ligand) stoichiometry and molar conductance data in ethanol indicate 1:1 electrolytes in all the lanthanide(III) chelates. The lanthanide (III) chelates with HMPOX are X-ray isomorphous. The magnetic moment values show little deviation from Van Vleck values. The electronic spectra, recorded at room temperature in methanol are dominated by ligand absorption bands and exhibit only slight shift and marked enhancement in the intensity of the bands. The implications of the IR spectral data are discussed. (author)