Physicochemical Investigation on Rare Earth Chelates of o-(N-α-Furfuraldimino)phenolate System

Department, of Chemistry, University of Jodhpur, Jodhpur-342 001 Manuscript received 23 February 1987, revised 10 December 1987, accepted 24 December 1987 o-(N-α(-Furfuraldimino)phenol (HFP), and its lanthanon chelates have been synthesised and studied by physicochemical techniques. Irving- Rossotti method has been followed to determine the dissociation constants of the ligand and formation constants of its lanthanon chelates in aqueous medium at different ionic strengths (0.01,0.05 and (0.1 M NaClO4) and temperatures (25, 35 and 45°). The solid laothanon chelates have been characterised by molecular mass, elemental analyses, conductance, magnetic, thermal and spectral analyses, and assigned 1 : 3 (metal-ligand) stoichiometry in which the lanthanon shows nine coordination number. Covalent nature of metal- ligand bond has been found to increase with the increase in atomic number of the central lanthanide ion