1089660-47-8Relevant academic research and scientific papers
Broad HOMO-LUMO gap tuning through the coordination of a single phosphine, aminophosphine or phosphite onto a Ru(tpy)(bpy)2+ core
Dixon, Isabelle M.,Lebon, Emilie,Loustau, Gilles,Sutra, Pierre,Vendier, Laure,Igau, Alain,Juris, Alberto
, p. 5627 - 5635 (2008)
The synthesis of new ruthenium(ii) terpyridine bipyridine complexes bearing a phosphorus(iii) ligand is presented. The steric and electronic properties of the phosphorus ligand were varied using aminophosphines, alkyl and aryl phosphites and the bulky tri(isopropyl)phosphine. All complexes were characterized by multi-nuclear NMR spectroscopy, mass spectrometry and X-ray diffraction analysis. The electronic properties of the complexes were probed by cyclic voltammetry, absorption and luminescence spectroscopy. The complexes do not show luminescence at room temperature, whereas at 77 K in an alcoholic matrix, emission is observed in the range 600-650 nm with lifetimes of 3.5-5.5 μs, originating from 3MLCT states. The MLCT transition spans over 65 nm, which corresponds to a variation of 0.4 eV in the HOMO-LUMO gap. The oxidation potential of the ruthenium varies over a broad range of 290 mV, from +1.32 V vs. SCE with L = PiPr3 to +1.61 V vs. SCE with L = P(OPh)3. This range is unprecedented upon the variation of a single monodentate ligand coordinated by the same heteroatom in the same oxidation and charge states. This work underlines the specific capacity of phosphorus in bringing up a large variety of electronic properties by changing its substituents.
