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.

Graphical abstractThe synthesis and crystal structures of two new ruthenium phosphine complexes [Ru(tpy)(bpy)(PR3)]2+ (R = Ph, Cy) are reported. Combined electrochemical and UV–Vis analyses show that both steric effects and net donor power (i.e. ability to transfer electron density to the metal) of the phosphine ligand can be used to modulate the redox properties and the frontier orbitals energy gap of the complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide