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

The synthesis and characterisation of copper, cobalt, nickel and zinc compo unds with sulfamethizole (4-amino-N-(5-methyl-1,3,4-thiadiazole-2-yl)sulfan ilamide) (Hsmtz) are described. The first crystal structures of ternary sul famethizole complexes are reported. The crystal structures of Cu(smtz)(2)(p y)(2)(OH2). H2O (1), M(smtz)(2)(py)(2)(OH2)(2) [M=Co (2), Ni (3)] and {Cu(s mtz)(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 ot her compounds the metal ion presents a distorted octahedral environment. In compounds 1, 2 and 3 the deprotonated sulfamethizole acts as monodentate l igand coordinating through the thiadiazole N atom and in compound 5 it beha ves as a bridge linking two metal cations via the thiadiazole and the amino nitrogen atoms. The IR, electronic, EPR and thermal data are consistent wi th the crystal structures. (C) 2000 Elsevier Science Ltd. All rights reserv ed.