Syntheses and characterisation of mercury complexes of sulfadiazine, sulfamerazine and sulfamethazine

The triple sulfa drugs, sulfadiazine, sulfamerazine and sulfamethazine, form a large number of metal complexes in different solvent media. The present studies show the synthesis and characterization of the Hg(II) complexes of sulfadiazine 1, sulfamerazine 2 and sulfamethazine 3 in dimethylformamide solution in presence of ammonia. The compounds were characterised by spectroscopic methods and crystal structures of the complexes were determined. All the compounds, 1, 2 and 3, crystallise in monoclinic crystal systems with the space groups of C2/c, C2/c and P21/c, respectively. Compounds 1 and 3 have eight coordinate ‘2+6’ geometries, with two tridentate sulfonamide ions and two DMF molecules in the coordination sphere. Complex 2 has a six co-ordinate, ‘2+4’ geometry which contains a short linear N–Hg–N moiety from co-ordinated sulfonamides. The IR spectral data suggest the binding of mercury atom to the sulfonamidic nitrogen atoms in agreement with the crystal structure determination.

Graphical abstractHg(II) complexes of sulfadiazine 1, sulfamerazine 2 and sulfamethazine 3 were synthesised and their nature investigated by spectroscopic methods, including single crystal X-ray diffraction. In the solid state compounds 1 and 3 have eight coordinate ‘2+6’ geometries, with two tridentate sulfonamide ions and two DMF molecules in the coordination sphere, while complex 2 has a six co-ordinate, ‘2+4’ geometry.Figure optionsDownload full-size imageDownload as PowerPoint slide