Metal-binding in chelation therapy: X-ray crystal structure of a copper(I)–copper(II) complex of D-penicillamine

Abstract

The purple complex formed by copper with D-penicillamine at physiological pH is shown to be a [Cu^I₈Cu^II₆L₁₂Cl]^5– cluster [L =^–S-C(Me₂)–CH(NH₂)CO₂^–] in which the eight S₃-co-ordinated Cu^I atoms surround a central chloride ion; each of the six Cu^II atoms is N₂S₂- co-ordinated by two chelating L ligands whose carboxygroups are on the surface of the cluster.