A DINUCLEAR COMPLEX OF THE THIOPURINE DRUG AZATHIOPRINE - [CU2CL4(MU-AZATHIOPRINE)(2)].4DMF

In the title centrosymmetric dinuclear complex, lylthio)-7H-purine-N-3 :N-9]bis[dichlorocopper(II)] tetrakis(dimethylformamide) solvate, [Cu2 Cl4(C9H7N7O2S)(2)].4C(3)H(7)NO, the two Cu atoms are each coordinated by two chloro and two N3:N9-bridging neutral azathioprine ligands. The coordination geometry of each Cu atom is strongly distorted square pl anar. The Cu ... Cu distance within the dinuclear unit is 2.939(2) Ang strom. Azathioprine exhibits a conformation in which there is a trans arrangement of the C5-C6 and S6-C10 bonds with respect to C6-S6, and i n which the imidazole substituent at S6 points away from the imidazole ring of the purine moiety. The imidazole plane is approximately perpe ndicular to the purine plane, with a corresponding dihedral angle of 7 2.1 (3)degrees.