Mono- versus binuclear copper(II) complexes in phosphodiester hydrolysis

Article abstract of DOI:10.1002/ejic.200500595

Mono- and dinuclear copper(II) complexes [Cu(L¹OH)]-(CF ₃SO₃)₂ (1) and [Cu₂(L ²O)](CF₃SO₃)₃ (2) have been synthesized and characterized by X-ray crystallography. Complexes 1 and 2 were then tested as catalysts for the hydrolysis of bis(p-nitrophenyl)phosphate (BNPP). At pH 6, the dinuclear complex 2 was found to be 20-fold more active than complex 1 and the reaction up to 600-fold faster than the un-promoted reaction. On the basis of potentiometric studies, we were able to demonstrate that the bis(aqua)copper complex was the active species by the formation of a ternary complex in which one copper atom binds to a hydroxide and the second, to the substrate. We also propose that BNPP reacts with the bis(aqua)copper complex to give a stable, hydrolytically inactive BNPP-2 complex (3). Wiley-VCH Verlag GmbH & Co. KGaA, 2006.