title: Investigation of a new bis(carboxylate)triazole-based anchoring ligand for dye solar cell chromophore complexes.
abstract: A novel anchoring ligand for dye-sensitised solar cell chromophoric complexes, 1-(2,2'-bipyrid-4-yl)-1,2,3-triazole-4,5-dicarboxylic acid (dctzbpy), is described. The new dye complexes [Ru(bpy)2(dctzbpy)][PF6]2(AS16), [Ir(ppy)2(dctzbpy)][PF6] (AS17) and [Re(dctzbpy)(CO)3Cl] (AS18) were prepared in a two stage procedure with intermediate isolation of their diester analogues, AS16-Et2, AS17-Et2 and AS18-Et2 respectively. Electrochemical analysis of AS16-Et2, AS17-Et2 and AS18-Et2 reveal reduction potentials in the range -1.50 to -1.59 V (vs. Fc+/Fc) which are cathodically shifted with respect to that of the model complex [Ru(bpy)2(dcbH2)]2+(1) (Ered= -1.34 V, dcbH2= 2,2'-bipyridyl-4,4'-dicarboxylic acid). This therefore demonstrates that the LUMO of the complex is correctly positioned for favourable electron transfer into the TiO2conduction band upon photoexcitation. The higher energy LUMOs for AS16 to AS18 and a larger HOMO-LUMO gap result in blue-shifted absorption spectra and hence reduced light harvesting efficiency relative to their dcbH2analogues. Preliminary tests on TiO2n-type and NiO p-type DSSCs have been carried out. In the cases of the Ir(iii) and Re(i) based dyes AS17 and AS18 these show inferior performance to their dcbH2analogues. However, the Ru(ii) dye AS16 (η = 0.61%) exhibits significantly greater efficiency than 1 (η = 0.1%). In a p-type cell AS16 shows the highest photovoltaic efficiency (η = 0.028%), almost three times that of cells incorporating the benchmark dye coumarin C343.
authors.affiliation: Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK. p.i.elliott@hud.ac.uk.
authors.forename: Alessandro
authors.identifier: http://orcid.org/0000-0001-7993-4268
authors.initials: A
authors.lastname: Sinopoli
authors.affiliation: School of Chemistry, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. elizabeth.gibson@ncl.ac.uk.
authors.forename: Fiona A
authors.initials: FA
authors.lastname: Black
authors.affiliation: School of Chemistry, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. elizabeth.gibson@ncl.ac.uk.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Wood
authors.affiliation: School of Chemistry, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. elizabeth.gibson@ncl.ac.uk.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Gibson
authors.affiliation: Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK. p.i.elliott@hud.ac.uk.
authors.forename: Paul I P
authors.initials: PI
authors.lastname: Elliott
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D011211:Electric Power Supplies; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry; D012993:Solar Energy; D014230:Triazoles / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D004396:Coloring Agents; D008024:Ligands; D009942:Organometallic Compounds; D014230:Triazoles; D012428:Ruthenium