Comparison of donor properties of N-heterocyclic rings in Ruthenium complexes by Quantum mechanical calculations

The Ru complexes are synthesized and electron transfer process has been analyzed by theoretical studies. The electron donating ability from the donor sites for the ligand towards Ru can be understood from the reduction of charge density of these atomic sites. Formation of stable complexes is expected from the extent of charge transfer from ligand to Ru. Moreover coordinating ability of donor sites is closely related to the stability of the complex leading to the variation of redox potential. The computed values of oxidation (OX) and reduction (RD) for these complexes vary significantly which are related to frontier energy gap.