Physicochemical analysis of ruthenium(II) sensitizers of 1,2,3-triazole-derived mesoionic carbene and cyclometalating ligands.
A series of heteroleptic bis(tridentate) ruthenium(II) complexes bearing ligands featuring 1,2,3-triazolide and 1,2,3-triazolylidene units are presented. The synthesis of the C^N^N-coordinated ruthenium(II) triazolide complex is achieved by direct C-H activation, which is enabled by the use of a 1,5-disubstituted triazole. By postcomplexation alkylation, the ruthenium(II) 1,2,3-triazolide complex can be converted to the corresponding 1,2,3-triazolylidene complex. Additionally, a ruthenium(II) complex featuring a C^N^C-coordinating bis(1,2,3-triazolylidene)pyridine ligand is prepared via transmetalation from a silver(I) triazolylidene precursor. The electronic consequences of the carbanion and mesoionic carbene donors are studied both experimentally and computationally. The presented complexes exhibit a broad absorption in the visible region as well as long lifetimes of the charge-separated excited state suggesting their application in photoredox catalysis and photovoltaics. Testing of the dyes in a conventional dye-sensitized solar cell (DSSC) generates, however, only modest power conversion efficiencies (PCEs).
Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena , Humboldtstr. 10, 07743 Jena, Germany.
Stephan
S
Sinn
Benjamin
B
Schulze
Christian
C
Friebe
Douglas G
DG
Brown
Michael
M
Jäger
Esra
E
Altuntaş
Joachim
J
Kübel
Oliver
O
Guntner
Curtis P
CP
Berlinguette
Benjamin
B
Dietzek
Ulrich S
US
Schubert