CARBOXYLATE BRIDGING OF AMINO-ACIDS IN DINUCLEAR MACROCYCLIC NICKEL(II) COMPLEXES

The dinuclear nickel(II) complex [Ni2L(MeOH)2(ClO4)2].2NEt3HClO4, derived from a tetraazadiphenol macrocyclic ligand H2L, on reaction with glycine, beta-alanine and glycylglycine affords the mu-carboxylato complexes of composition [Ni2L(-O2C-NH3+)(H2O)2][ClO2]2.nH2O. The structure of [Ni2L(mu-O2CCH2-NH3) (H2O)2][ClO4]2.2H2O has been determined: monoclinic, space group C(c), with a - 17.465(2), b = 21.834(2), c = 11.480(1) angstrom, beta = 115.27(2)-degrees and Z = 4. The structure was solved by direct methods and refined to R = 0.047 and R' = 0.064.