title: Synthesis of phosphonic acid derivatized bipyridine ligands and their ruthenium complexes.
abstract: Water-stable, surface-bound chromophores, catalysts, and assemblies are an essential element in dye-sensitized photoelectrosynthesis cells for the generation of solar fuels by water splitting and CO2 reduction to CO, other oxygenates, or hydrocarbons. Phosphonic acid derivatives provide a basis for stable chemical binding on metal oxide surfaces. We report here the efficient synthesis of 4,4'-bis(diethylphosphonomethyl)-2,2'-bipyridine and 4,4'-bis(diethylphosphonate)-2,2'-bipyridine, as well as the mono-, bis-, and tris-substituted ruthenium complexes, [Ru(bpy)2(Pbpy)](2+), [Ru(bpy)(Pbpy)2](2+), [Ru(Pbpy)3](2+), [Ru(bpy)2(CPbpy)](2+), [Ru(bpy)(CPbpy)2](2+), and [Ru(CPbpy)3](2+) [bpy = 2,2'-bipyridine; Pbpy = 4,4'-bis(phosphonic acid)-2,2'-bipyridine; CPbpy = 4,4'-bis(methylphosphonic acid)-2,2'-bipyridine].
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill , CB 3290, Chapel Hill, North Carolina 27599, United States.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Norris
authors.forename: Javier J
authors.initials: JJ
authors.lastname: Concepcion
authors.forename: Christopher R K
authors.initials: CR
authors.lastname: Glasson
authors.forename: Zhen
authors.initials: Z
authors.lastname: Fang
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Lapides
authors.forename: Dennis L
authors.initials: DL
authors.lastname: Ashford
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Templeton
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Meyer