AQUEOUS CHEMISTRY OF SOME BIO-METAL (II) COMPLEXES WITH NICOTINIC ACID AND ADENINE

Abstract

Abstract

 Aqueous  chemistry  of  some  bio-metal complexes of  Cu(II), Ni(II),Co(II), and Cd(II), with nicotinic acid and adenine were investigations pH-metrically on  computer based programme. The mixed ligand complex formation equilibria of these complexes in aqueous solutionhaving constant ionic strength I=0.1 mol/dm³NaNO₃ and 37±0.2°C& applied for determination of complexationbehaviour of (1:1) binaryML₁&ML₂and (1:1:1) ternary ML₁L₂species. Stability constant have been determined throughthe method suggested by Irving & Rossetti and further refined through Stability Constant of Generalized Species (SCOGS)computer program. The percentage of species distribution curves have been demonstrated with the help of ORIGIN 6.1 software& plotted as a function ofpH. The highest percentage of ternary species of Cu(II)L₁L₂, is 67.4 at ~6.1 pH,Co(II)L₁L₂is 82.9 at ~7.3 pH,Cd(II)L₁L₂is 96.2 at~8-8.2 pH&Ni(II)L₁L₂is93.2at~7.4 pH which is also determined with the help of software.

Keywords Ternary chelates, bio-metal ions, stability constants, SCOGS.