Regio-Directed Synthesis of a Zn~(II)Fe~(II) Complex from an Unsymmetrical Ligand and Its Relevance to Purple Acid Phosphatases

摘要

A new heterodinuclear Zn~(II)Fe~(II) μ-phenoxy complex has been prepared and isolated from the unsymmetrical ligand 2-{[bis(2-hydroxybenzyl)]amino}methyl-6-{[2-pyridinylmethyl)amino]methyl}-4-methylphenol (H_3L~1), which provides two distinct N- and O-rich donor sets. The regioselective complexation is confirmed in solution by ~1H NMR studies (comparison of the spectra obtained from H_3L~1 and HL~2-a ligand with only the N-donor set available-and a zinc salt). The crystal structure of the bis(μ-diphenylphosphato)Zn~(II)Fe~(II) complex [ZnFeL~1{O_2P(OP)_2}_2] (1) is reported. The NO_5 coordination sphere around the Fe~(III) reproduces, for the first time, the oxygen-rich coordination sphere around iron(III) in red kidney beam purple acid phosphatase (KBPAP).