Physico-chemical studies on mixed ligand complexes of Zn2+, Mn2+, Co2+ and VO2+ with all cis-1,2,3,4-cyclopentanetetra carboxylic acid (CPTA) as a primary ligand and crotonic acid as a secondary ligand

The formation of 1:1:1 ternary complexes of Zn2+, Mn2+, Co2+, and VO2+ with all cis-1,2,3,4-cyclopentanetetra carboxylic acid (CTPA) as a primary ligand and crotonic acid as a secondary ligand have been studied potentiometrically by employing the modified method of Irving and Rossotti at 30 deg C, 40 deg C and 50 deg C and keeping the ionic strength constant μ=0.2M(KNO3). The stability constants determined follows the order: VO2+ > Co2+ > Mn2+ > Zn2+. The thermodynamic parameters like free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) have also been calculated using the standard equations. (author)