Tuning visible-light absorption properties of Ru–diacetylide complexes: simple access to colorful efficient dyes for DSSCs

Abstract

A series of s-dialkynyl ruthenium complexes showing a D-p-[M]-p-A structure (where [M] ¼ [Ru(dppe) 2 ], dppe ¼ bisdiphenylphosphinoethane) were designed and synthesized for dye-sensitized solar cell (DSSC)applications. The molecular structure of these highly modular organometallic complexes was fine-tuned through the introduction of a bithiophene, rhodanine or benzothiadiazole unit. This original molecular engineering approach combined with convergent synthetic pathways thus afforded efficient photosensitizers with tunable colors across the visible spectrum, ranging from red to purple, blue and blue-green dyes. The optoelectronic properties of the new complexes were fully assessed and the dyes were tested in standard single-dye devices as well as in co-sensitized DSSCs, yielding 7.5% power conversion efficiency in the presence of an iodine-based liquid electrolyte. ; Tel: +33 5 40 00 24 25 † Electronic supplementary information (ESI) available: Materials and methods, synthetic procedures, compound characterization, and theoretical calculation details. See a DE ge ¼ main transition energy. b l ge ¼ calculated l max . c f ge ¼ oscillator strength. d Only the transitions with coefficients higher than 0.15 are given. e L ¼ spatial overlap. f q CT ¼ quantity of transferred charge. g D CT ¼ distance between the barycentres of the density depletion and density increment zones related to the CT excitation. J. Mater. Chem. AThis journal is

Ruthenium Complexes as Sensitizers in Dye-Sensitized Solar Cells

“…Moreover, we should not sacrifice one of these principles to gain in another, as it was in the last two Due to the successful performance of ruthenium polypyridine complexes with their MLCT transition and later of D-π-A organic and porphyrin sensitizers with their D-A and π-π* transitions, other possible alternatives earned less attention. Recently, promising results were obtained with heteroleptic ruthenium diacetylid complexes [130,131]. Regarding the first row transition metals, only copper [132][133][134] and iron complexes [135,136] have gained a significant attention in the context of sensitization.…”

Design and synthesis of novel organometallic dyes for NiO sensitization and photo-electrochemical applications

“…Some of us recently reported the preparation and study of asymmetric ruthenium-diacetylide organometallic complexes as efficient photosensitizers for TiO 2 in n -type DSSCs[17,18] and for NiO in p-type DSSCs. [19] Besides, another type of organometallic complexes including the [Ru(dppe) 2 ] core has been previously reported, namely mixed alkynyl-allenylidene complexes.…”

H2-Evolving Dye-Sensitized Photocathode Based on a Ruthenium–Diacetylide/Cobaloxime Supramolecular Assembly

“…In these spectra, intense absorption bands are observed in the UV region, below 300 nm, characteristic of the phenyl substituents of the diphosphine ligands. [42] According to previous reports, the intense absorption band centered at ca. 355 nm can be attributed to electronic transitions involving the electron-rich triphenylamine ligand.…”

“…The trans-ditopic structure of the metal centre was confirmed by the 31 P NMR spectrum which shows a singlet for the four equivalent phosphorus atoms, with  ≈ 53 ppm characteristic of the Ru-diacetylide structure. [41][42][43] Characteristic peaks were observed on the infra-red spectra, at ca. 2195 cm -1 for the νC≡C of the ethynylpyridine unit and at ca.…”