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)(dctzbpy)][PF] (AS16), [Ir(ppy)(dctzbpy)][PF] (AS17) and [Re(dctzbpy)(CO)Cl] (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)(dcbH)] (1) (E = -1.34 V, dcbH = 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 TiO conduction 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 dcbH analogues. Preliminary tests on TiO n-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 dcbH analogues. 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.

Heteromultimetallic compounds based on polyfunctional carboxylate linkers

“…However, the broad profile of this band did not permit the Re(I)-centred transitions to be distinguished from those arising from the Ru(II) metal centres. In good agreement with the data reported in the literature, 22 the excitation of the MLCT features of a dilute (10 -5 M) acetonitrile solution of the complex [ReCl(CO)3(µ-H2dcbpy)] (4) produced a weak emission centred at ca. 720 nm ( Figure 4 and Table 1).…”

A Comparative Investigation of the Role of the Anchoring Group on Perylene Monoimide Dyes in NiO‐Based Dye‐Sensitized Solar Cells

“…which is aw eaker Lewis acid than Ti IV in TiO 2 .F or fast hole injection into the NiO valence band, the HOMO of the dye must mix with the valence band, which implies that the anchoring group orbitalsm ust give as ignificantc ontribution to the HOMO.T his is the opposites ituation for TiO 2 sensitizers, which must be composed of electron-deficient anchoring groupso n which the LUMO should be delocalized. [16] We have investigated the replacement of carboxylic acid by catechol, [17] carbodithioic acid, [17] phosphonic acid, [17] acetyla cetone( acac), [18] alkoxysilane [19] and other teams have investigated pyridine, [20][21][22] di(carboxylic acid)pyrrole, [23,24] hydroxamic acid, [25] and di(carboxylic acid)triazole [26] as alternative anchoring groups for NiO photocathodes.O wing to the scarcity of systematic studies on NiO anchoring groups, we have been interested to investigate the properties of as eries of dyes that differ only by the nature of the anchoring group ( Figure 1).…”

“…This is the opposite situation for TiO 2 sensitizers, which must be composed of electron‐deficient anchoring groups on which the LUMO should be delocalized . We have investigated the replacement of carboxylic acid by catechol, carbodithioic acid, phosphonic acid, acetyl acetone (acac), alkoxysilane and other teams have investigated pyridine, di(carboxylic acid)pyrrole, hydroxamic acid, and di(carboxylic acid)triazole as alternative anchoring groups for NiO photocathodes. Owing to the scarcity of systematic studies on NiO anchoring groups, we have been interested to investigate the properties of a series of dyes that differ only by the nature of the anchoring group (Figure ).…”

Copper(II) and Zinc(II) Complexes of Mono- and Bis-1,2,3-Triazolesubstituted Heterocyclic Ligands

“…[1][2][3][4][5][6] Regioselective formation of 1,4-disubstituted 1,2,3triazole-based mono-, bi-or multidentate chelating ligands has received considerable attention because of its broad application in drug development, optics, redox sensing, fluorescence and catalysis. 2,3,[7][8][9][10][11][12][13] The large dipole moment of triazoles, around 5 D, allows easy formation of hydrogen bonds, as well as dipoledipole and π-interactions, which can favour their binding to biological targets and improve their solubility. 14 Moreover, 1,2,3triazoles are found to be versatile ligands that can coordinate to metals through the N3, N2 and C5 donor sites, with preferential coordination at the N3 atom.…”