SEPARATION AND SPECTROSCOPIC CHARACTERIZATION OF NEW METAL-CHELATES OF 8-ARYLAZO-6-FORMYL-7-HYDROXY-5-METHOXY-2-METHYL CHROMONES

Transition metal chelates of the title compounds have been prepared an d characterized by elemental analyses, i.r., H-1-n.m.r., electronic sp ectra, thermogravimetric analysis, conductometric and magnetic measure ments. Chelates of general formulae MLjX . nH(2)O for 1:1 (M:L), where X = OH- or Cl-, j = 1 or 2, n = 1-4 and M = VO2+, Cr3+, Mn2+, Fe2+, C o2+, Ni2+, Cu2+ and Zn2+ ions or ML2 for 1:2 (M:L) Ni-(1a), ML2 . 2H(2 )O where M = Co2+, Ni2+ and Cu2+ or M(2)LjX . nH(2)O for 2:1 (M:L) Cr3 +, Fe2+, Ni2+ and Cu2+, L = Ligand, have been prepared. I.r. and H-1-n .m.r. spectra indicate that the aldehydic group in position six and th e hydroxylic group in position seven are involved in chelation in the 1:1 and 1:2 (M:L) chelates, whereas for 2:1 (M:L) chelates with (1c), the interaction of the metal ion takes place through CHO, OH, CO2H and N=N groups. Tetrahedral, octahedral and square planar geometries are proposed for the chelates based on their electronic spectra and magnet ic moments.