Circular Dichroism Studies of Complexation of Antibiotic (+)- Cephradine With Cr(III), Co(II) and Ni(II) in Methanol: Water (80:20) Solution

Authors: Nasir AHMAD, Javed SAFDER, Christy MUNIR

Abstract: Circular dichroism (CD) studies have been utilized to investigate complexation of antibiotic (+)-cephardine with Cr(III), Co(II) and Ni(II) ions in methanol: water (80:20 v/v) solution. The optimum conditions of pH, stoichiometry and time for achieving equilibrium for maximum complexation in these systems are determined. The CD spectra of these complex ions consist of 2-3 Cotton bands between 16,129-25,994 cm^{-1} with differential absorptivity 0.0046-0.428 deg. L mol^{-1} cm^{-1} and bands are assigned to electronic transitions. The formation constants of these complexes in mixed solvent are reported.

Keywords: CD studies, (+)-cephardine, Chromium (III)-(+)- ceph. complex, Cobalt (II)-(+)-ceph. complex, Nickel (II)-(+)-ceph. complex, Stability constants.

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