Potentiometric Studies of Ruthenium (Iii)- Ethylenediamine Tetracetate Complex With Some Bioligands

*R. Madhusuda Raju and Venkat Anand Pannala

Department of Chemistry, Osmania University, Hyderabad- 500 007 (India)

Stability constants for ternary complexes of ruthenium (III) with edta as primary ligand and orthophenanthroline, a, a1-bipyridyl adenine, adenosine, guanine and guanosine as secondary ligands under nitrogen and oxygen atmosphere were investigated potentiometrically in 1:1:1 molar ratio at 35°C with constant ionic strength of 0.1 M KCl. It was observed that there was no interaction with molecular oxygen when studied under oxygen atmospheric indicating the stabilization to Rhuthenium (III) ion by coordinated secondary ligand. The tentative structures proposed were of the form [Ru(edta)(L)] where edta acts as a tetradentate ligand and L (secondary ligands) act as bidentate ligand in the octahedral ruthenium complexes.

Ruthenium(III) edta; Pyrimidine bases; Nucleosides; Orthophenanthroline; a; a1 bipyridyl; pH metry