Synthesis and Characterization of an Octanuclear Mixed-Ligand Copper(II) Complex of the Immunosuppressant Thiopurine Drug Azathioprine.

An octanuclear mixed-ligand copper(II) complex of the immunosuppressant drug azathioprine (AZA) and 2,2,6,6-tetramethylheptane-3,5-dione (THD), [{Cu(4)(AZA(-))(2)(THD(-))(5)(OH(-))}(2)].2CH(3)CN, has been synthesized and characterized by X-ray crystallography and by mass spectrometric and magnetic measurements. Eight copper(II) ions, four monodeprotonated azathioprine(-) ligands, ten monodeprotonated THD(-) ligands, and two hydroxide anions are assembled to form a centrosymmetric, octanuclear molecule, where two tetranuclear moieties of the molecule are connected by four coordination bonds between copper atoms and the N(3) and N(9) atoms of two different AZA ligands.