Carboxylate bridging of amino acids in dinuclear macrocyclic nickel(II) complexes

Abstract

The dinuclear nickel(II) complex [Ni2L(MeOH)2(ClO4)2]·2NEt3HClO4, derived from a tetraazadiphenol macrocyclic ligand H2L, on reaction with glycine, β-alanine and glycylglycine affords the µ-carboxylato complexes of composition [Ni2L(–O2C–NH3+)(H2O)2][ClO4]2·nH2O. The structure of [Ni2L(µ-O2CCH2NH3)(H2O)2][ClO4]2·2H2O has been determined: monoclinic, space group Cc, with a= 17.465(2), b= 21.834(2), c= 11.480(1)Å, β= 115.27(2)° and Z= 4. The structure was solved by direct methods and refined to R= 0.047 and R′= 0.064.