Coordination chemistry of sulfamethizole:: crystal structures of [Cu(sulfamethizolate)2(py)2(OH2)]•H2O, [M(sulfamethizolate)2(py)2(OH2)2] [M = Co and Ni] and {Cu(sulfamethizolate)2(dmf)2}∞

The synthesis and characterisation of copper, cobalt, nickel and zinc compounds with sulfamethizole (4-amino-N-(5-methyl-1,3,4-thiadiazole-2-yl)sulfanilamide) (Hsmtz) are described. The first crystal structures of ternary sulfamethizole complexes are reported. The crystal structures of Cu(smtz)(2)(py)(2)(OH2). H2O (1), M(smtz)(2)(py)(2)(OH2)(2) [M=Co (2), Ni (3)] and {Cu(smtz)(2)(dmf)(2)}(infinity) (5) were determined by X-ray diffraction. The Cu(II) ion exhibits a square pyramidal geometry in complex 1. while in the other compounds the metal ion presents a distorted octahedral environment. In compounds 1, 2 and 3 the deprotonated sulfamethizole acts as monodentate ligand coordinating through the thiadiazole N atom and in compound 5 it behaves as a bridge linking two metal cations via the thiadiazole and the amino nitrogen atoms. The IR, electronic, EPR and thermal data are consistent with the crystal structures. (C) 2000 Elsevier Science Ltd. All rights reserved.