POLYMER COMPLEXES .25. COMPLEXING ABILITY OF POLY(5-VINYLSALICYLIDENE-2-AMINOPYRIDINE) TOWARDS DIFFERENT METAL(II) SALTS

Mononuclear and binuclear complexes of poly(5-vinylsalicylidene-2-amin opyridine)dagger were prepared by the reaction of the homopolymer with copper(II), cobalt(II), nickel(II), cadmium(II), dioxouranium(VI) and palladium(II) salts. Metal(II) acetates and palladium chloride were f ound to give mononuclear complexes, while cupric chloride gave a binuc lear complex. The polymer complexes have been characterized on the bas is of elemental analysis, u.v. and i.r. spectroscopy, and magnetic sus ceptibility measurements. The stereochemistry and the nature of the co mplexes are markedly dependent upon the molar ratios of the reactants, the pH of the system and the nature of the anions involved. In all of the complexes the homopolymer was chelated to the metal ion through t he nitrogen atom of the azomethine group and the oxygen atom of the ph enolic group. The low value of the magnetic moment of the binuclear co pper complex is due to an antiferromagnetic interaction between two ad jacent copper atoms. The ligand field parameters have been calculated and related to the electronic environments. The electronic absorption of the homopolymer was investigated in organic solvents of varying pol arities and buffer solutions of different pH, and the behaviour in the latter has been utilized in calculating the pK(a) of the phenol group .