Physicochemical studies of complexes of some transition metal ions with rifampicin

From potentiometric equilibrium measurements of hydrogen-ion concentration at 25 and 35 with an ionic strength of 0.1 M [KCl] in 50% [v/v] aqueous methanol, the values of thermodynamic constants of rifampicin complexes with Co [II], Ni [II] Cu [II] and Zn [II] have been determined. Probable structures of the metal chelates are inferred from the elemental analysis, conductance measurements, IR and electronic spectra