title: Engineering of Ruthenium(II) Photosensitizers with Non-Innocent Oxyquinolate and Carboxyamidoquinolate Ligands for Dye-Sensitized Solar Cells.
abstract: An alternative approach to replacing the isothiocyantate ligands of the N3 photosensitizer with light-harvesting bidentate ligands is investigated for application in dye-sensitized solar cells (DSSCs). An in-depth theoretical analysis has been applied to investigate the optical and redox properties of four non-innocent ligand platforms, which is then corroborated with experiment. Taking advantage of the 5- and 7-positions of 8-oxyquinolate, or the carboxyaryl ring system of the N-arylcarboxy-8-amidoquinolate ligand, fluorinated aryl substituents are demonstrated as an effective means of tuning complex redox potentials and light-harvesting properties. The non-innocent character, resulting from mixing of both the central metal-dπ and ligand-π manifolds, generates hybrid metal-ligand frontier orbitals. These play a major role by contributing to the redox properties and visible electronic transitions, and promoting an improved power conversion efficiency in a Ru DSSC device featuring non-innocent ligands.
authors.affiliation: Department of Chemistry, University of Massachusetts Boston, Boston, MA, 02125, USA.
authors.forename: Ken T
authors.initials: KT
authors.lastname: Ngo
authors.affiliation: Department of Chemistry, University of Massachusetts Boston, Boston, MA, 02125, USA.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Lee
authors.affiliation: Department of Chemistry, University of Massachusetts Boston, Boston, MA, 02125, USA.
authors.forename: Sashari D
authors.initials: SD
authors.lastname: Pinnace
authors.affiliation: Department of Chemistry, University of Massachusetts Boston, Boston, MA, 02125, USA.
authors.forename: Jonathan
authors.identifier: http://orcid.org/0000-0003-2397-9162
authors.initials: J
authors.lastname: Rochford
keywords: charge transfer; density functional calculations; non-innocent ligand; photochemistry; ruthenium