Effect of propanediol on chemical speciation of phenanthroline complexes of toxic metals

Department of Chemistry, Ani! Neerukonda Institute of Technology and Sciences, Sangivalasa,

Visakhapatnam-531 162, Andhra Pradesh, India

school of Chemistry, Andhra University, Visakhapatnam-530 003, Andhra Pradesh, India

E-mail : gollapallinr@yahoo.com

Manuscript received 16 June 2011, revised 15 November 2011, accepted 21 November 2011

The stability of the binary complexes of toxic metal ions such as Pb^II , Cd^ll and Hg^ll with 1,10-phenanthrolinc is studied by pH metry in (0.0-60.0% v/v) 1,2-propanediol-water mixtures at 303 K and 0.16 mol L^-1 ionic strength. The trend in β values of the metal-ligand complexes with the dielectric constant is explained on the basis of electrostatic and non-electrostatic forces.