Cyclometalated Ru(ii) complexes with tunable redox and optical properties for dye-sensitized solar cells

Abstract

A series of cyclometalated Ru(II) complexes with 2-arylbenzimidazoles antenna ligands bearing electron-donor/withdrawing substituents and anchoring 4,4′-dimethoxycarbonyl-2,2′-bipyridine have been prepared and their structure, optical and electrochemical properties have been studied. The...

Tailoring the π-system of benzimidazole ligands towards stable light-harvesting cyclometalated iridium(iii) complexes

“…The more pronounced enhancement of absorbance observed for the complex 2 correlates well with optical data for naphtalene-benzimidazole and naphthalene-thiazole complexes studied in the literature. 51,70 Complex 4 demonstrates the most intense light absorption at 450-550 nm in the series with ε values ranging from 5000 to 16 000 M −1 cm −1 which are an order of magnitude greater than those of the "parent" 1,2-diphenylbenzimidazole-based Ir(III) complex and comparable to those of commercial Ru(II) dyes 71 (Fig. S55 †) up to 510 nm.…”

Recent Investigations on Thiocyanate-Free Ruthenium(II) 2,2′-Bipyridyl Complexes for Dye-Sensitized Solar Cells

“…In 2020, Lavrova, Mishurinskiy et al [33] published five new ruthenium-based dyes having two anchoring dcmbipy ligands and a N-phenyl-2-arylbenzimidazole cyclometalating ligand bearing different substituents (complexes 12a-12e; Figure 6). The main In compounds 10a, 10c, and 10e the trifluoromethyl groups were in the ortho and para positions with respect to the Ru-bound carbon atom of the phenyl ring, while in the case of 10b, 10d, and 10f they were in the meta positions.…”

“…In 2020, Lavrova, Mishurinskiy et al [33] published five new ruthenium-based dyes having two anchoring dcmbipy ligands and a N-phenyl-2-arylbenzimidazole cyclometalating ligand bearing different substituents (complexes 12a-12e; Figure 6). The main difference among the different dyes was represented by the substituents on the phenyl ring in position 2, being both electron-withdrawing (-NO 2 and -Cl) and electron-donating (-OMe and -NMe 2 ) groups.…”

“…0.5 mM dye in CH 3 CN or DCM. 32 0.3 mM dye in CH 3 CN:tBuOH 1:1 33. solutions A (97 mg/mL of Spiro-OMeTAD in chlorobenzene), B (175 mg/mL of LiTFSI in CH 3 CN) and C (46.6% v/v solution of TBP in CH 3 CN) were prepared separately.…”

Synthesis and crystal structures of N-H, N-phenyl and N-benzyl-2-(4-hexyloxyphenyl)benzimidazoles

“…Chemical context 2-Arylbenzimidazoles have attracted considerable attention as biologically active compounds (Vasava et al, 2020). They are also used as ligands in constructing cyclometalated iridium(III) and ruthenium(II) complexes for organic lightemitting diodes and photosensitizers in dye-sensitized solar cells (Bezzubov et al, 2020;Lavrova et al, 2020). For the latter application, the aryl unit of these ligands should contain -electron-donating substituents to increase the lightharvesting characteristics of the corresponding organometallic complexes (Aghazada & Nazeeruddin, 2018;Bezzubov et al, 2014Bezzubov et al, , 2016.…”