X-ray structure, redox and spectroscopic properties of ruthenium phosphine complexes [Ru(tpy)(bpy)(PPh3)]2+ and [Ru(tpy)(bpy)(PCy3)]2+

The synthesis and crystal structures of two new phosphine ruthenium polypyridine complexes [Ru(tpy)(bpy)(PR3)]2+ with R = Ph (1), Cy (2) are reported. Their geometrical parameters are intimately related to the electronic and steric properties of the phosphine ligand. Electrochemical and UV–Vis analyses showed the influence of the substituents of the coordinated phosphorus atom on the RuIII/RuII potential and on the frontier orbitals energy gap. The results are discussed in terms of steric effects and net donor power of the phosphine ligands.