Determination of thiocyanate with aromatic halosulphonamides in acid and alkaline media

Ten organic aromatic halosulphonamides, both mono and dihalo compounds, ranging from chlorosulphonamides to iodosulphonamides, have been prepared and characterized by their infrared and NMR spectra and successfully used for determining thiocyanate in its metal salts and complexes. The proposed procedures are simple, rapid and reproducible, with an error of about +/-0.8%. These procedures are also useful for computing the number of thiocyanate ligands present in the complexes. Comparison of the present results with those from the argentometric method shows excellent agreement. The oxidation involves an 8-electron change per thiocyanate ion with the chloro and bromosulphonamides and a 6-electron change with iodosulphonamides.