Potentiometric determination of formation constants of metal ion complexes with 4-hydrazinobenzofuro[3,2-d]pyrimidine Schiff base

Department of Chemistry, Gulbarga University, Gulbarga-585 106, India N. V. College, Gulbarga-585 102, India Manuscript received 21 June 2001, revised 20 August 2001, accepted 15 September 2001 Solution equilibrium studies on the complex formation of bivalent Mg, Co, Ni, Zn, Cd, Hg and Cu with the Schiff base de­rived from condensation of 4-hydrazinobenzofuro13,2-dIpyrimidine with 5-methylsalicylaldehyde by pH-titration technique at 30 ± 1° at a constant ionic strength, 0.1 M (NaCIO4) in 70 : 30% (v/v) alcohol-water medium, indicate the order : Cu > Co > Ni > Zn > Hg > Cd > Mg of stability constants of the complexes