METAL-COMPLEXES OF CEPHRADINE - SYNTHESIS AND EQUILIBRIUM STUDIES

The complex formation equilibria of the binary and ternary systems M(I I)-Cephradine and M(II)-2,2-Bipyridyl-Cephradine were investigated by a potentiometric technique at 25 degrees C and an ionic strength of 0. 1 M NaNO3 (M = Cu, Ni, Co, and Zn). The effect of dioxane as a solvent on the protonation constants of cephradine and the formation constant s of the Cu-cephradine complex was studied. The relative stability of each ternary complex was compared with that of the corresponding binar y complex in terms of Delta logK. The mode of ternary complex formatio n was ascertained by conductivity measurements. The copper(II), nickel (II), and cobalt(II) complexes of cephradine were synthesized and char acterized by elemental analysis, conductivity measurements, and IR spe ctra.