Complexes of Sulphadiamidine. Part II. Equilibrium and Thermodynamic Studies of Iron(II) and Iron(III) with Sulphadiamidine

Abstract

Binary complexes of 4-amino-N-(2,6-dimethyl-4-pyrimidinyl)benzenstilfonamide (sulphadiamidine) (HL) with Fe(II) and Fe(III) were studied at an ionic strength of 0. 1 M KNO₃ and at 25°C. The formation constants of these binary complexes were deteimined using the MIMQUAD program. The solid complexes were prepared and characterized by elemental analyses, electrolytic conductance, electronic, IR, mass spectra and thermogravimetric (TG, DTG and DTA) measurements. The ligand forms 1:2 complexes (metakligand). An octahedral geometry is suggested for the complexes where two coordination sites are occupied by two water molecules or one chloride ion and a water molecule, [ML₂(H₂O)_nCI_m], where M = Fe(II) (n = 2, m = 0) or Fe(III) (n=1, m=1) and HL = sulphadiamidine.