Synthesis and characterization of copper ibuprofenate complexes with 2,2'-bipyridine and 1,10-phenanthrolines and their hydrolytic activities in phosphate diester cleavage

Abstract

Abstract--A synthetic investigation of copper(II) ibuprofenate (lbup) addition compounds with 2,2'-bipyridine (bpy), I ,10-phenanthroline (phen) and 2,9-dimethyl- l ,10-phenanthroline (dmph) has led to the isolation of dinuclear adducts of the forms [Cu(Ibup)i(bpy)b- 4H 20 (1) and [Cu(Ibup)2 (phen)]2 (2) and a mononuclear adduct Cu(lbup)2 (dmph) (3). Spectroscopic data for adducts 1 and 2 are consistent with a dinuclear structure with two CuN 202 + 0 chromophors. Each copper is coordinated with two ibuprofenate bridges, a terminal diimine molecule and a monodentate ibuprofenate group complete five-coordination at each metal atom. Spectroscopic data for adduct 3 are consistent with a mononuclear structure having a very distorted square­ pyramidal CuN 202 +0 chromophore. The Cuu atom is coordinated to two nitrogen atoms from a chelating dmph ligand, two carboxylic oxygens of a bidentate ibuprofenate ion and an oxygen atom of a monodentate carboxylic group of a second ibuprofenate ion. The reduction of adduct (3) by ascorbic acid produced stable red copper(!) complex of the form [Cu(dmph)i] (Ibup) (4). Spectral data of this adduct indicated that the cation has distorted tetrahedral geometry about the copper atom. The effect of 1 and 2on the rate of hydrolysis of bis(p-nitrophenyl) phosphate (BNPP) have been examined in aqueous methanol solution at 70 C a nd pH7.4.