New Fe^IIIZn^II Complex Containing a Single Terminal Fe−O_p_henolate Bond as a Structural and Functional Model for the Active Site of Red Kidney Bean Purple Acid Phosphatase

The new heterodinuclear complex [FeIIIZnII(BPBPMP)(OAc)2]ClO4 (1) with the unsymmetrical N5O2 donor ligand 2-bis[{(2-pyridylmethyl)-aminomethyl}-6-{(2-hydroxybenzyl)(2-pyridylmethyl)}-aminomethyl]-4-methylphenol (H2BPBPMP) has been synthesized and characterized by X-ray crystallography, which reveals that the complex cation has an FeIIIZnII(μ-phenoxo)-bis(μ-carboxylato) core. Solution studies of 1 indicate that a pH-induced change of the bridging acetate occurs, and the formation of an active [(OH)FeIIIZnII(OH2)] species as a highly efficient catalyst under weakly acidic conditions for phosphate diesters hydrolysis is proposed.