194800-56-1Relevant articles and documents
Varying the electronic structure of surface-bound ruthenium(II) polypyridyl complexes
Ashford, Dennis L.,Brennaman, M. Kyle,Brown, Robert J.,Keinan, Shahar,Concepcion, Javier J.,Papanikolas, John M.,Templeton, Joseph L.,Meyer, Thomas J.
, p. 460 - 469 (2015/01/30)
In the design of light-harvesting chromophores for use in dye-sensitized photoelectrosynthesis cells (DSPECs), surface binding to metal oxides in aqueous solutions is often inhibited by synthetic difficulties. We report here a systematic synthesis approach for preparing a family of Ru(II) polypyridyl complexes of the type [Ru(4,4′-R2-bpy)2(4,4′-(PO3H2)2-bpy)]2+ (4,4′(PO3H2)2-bpy = [2,2′-bipyridine]-4,4′-diylbis(phosphonic acid); 4,4′-R2-bpy = 4,4′-R2-2,2′-bipyridine; and R = OCH3, CH3, H, or Br). In this series, the nature of the 4,4′-R2-bpy ligand is modified through the incorporation of electron-donating (R = OCH3 or CH3) or electron-withdrawing (R = Br) functionalities to tune redox potentials and excited-state energies. Electrochemical measurements show that the ground-state potentials, E′(Ru3+/2+), vary from 1.08 to 1.45 V (vs NHE) when the complexes are immobilized on TiO2 electrodes in aqueous HClO4 (0.1 M) as a result of increased Ru dπ-π back-bonding caused by the lowering of the π orbitals on the 4,4′-R2-bpy ligand. The same ligand variations cause a negligible shift in the metal-to-ligand charge-transfer absorption energies. Emission energies decrease from max = 644 to 708 nm across the series. Excited-state redox potentials are derived from single-mode Franck-Condon analyses of room-temperature emission spectra and are discussed in the context of DSPEC applications.
Facile and efficient syntheses of 2,2'-bipyridine-based bis(phosphonic) acids
Penicaud, Virginie,Odobel, Fabrice,Bujoli, Bruno
, p. 3689 - 3692 (2007/10/03)
The synthesis and characterization of new 2,2'-bipyridine ligands bearing two phosphonic acid groups either on the (4,4'), (5,5') or (6,6') positions are described.
