Premium
Trapped in Imidazole: How to Accumulate Multiple Photoelectrons on a Black‐Absorbing Ruthenium Complex
Author(s) -
Zedler Linda,
Kupfer Stephan,
de Moraes Inês Rabelo,
Wächtler Maria,
Beckert Rainer,
Schmitt Michael,
Popp Jürgen,
Rau Sven,
Dietzek Benjamin
Publication year - 2014
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201304937
Subject(s) - ruthenium , imidazole , photochemistry , electron transfer , chromophore , intramolecular force , chemistry , ligand (biochemistry) , raman spectroscopy , resonance (particle physics) , stereochemistry , catalysis , atomic physics , organic chemistry , optics , physics , biochemistry , receptor
Abstract Ruthenium dyes incorporating a 4 H ‐imidazole chromophore as a ligand exhibit a spectrally broad absorption in the UV/Vis region. Furthermore, they show the ability to store two electrons within the 4 H ‐imidazole ligand. These features render them promising molecular systems, for example, as inter‐ or intramolecular electron relays. To optimize the structures with respect to their electron‐storage capability, it is crucial to understand the impact of structural changes accompanying photoinduced charge transfer in the electronic intermediates of multistep electron‐transfer processes. The photophysical properties of these (reactive) intermediates might impact the function of the molecular systems quite substantially. However, the spectroscopic study of short‐lived intermediates in stepwise multielectron‐transfer processes is experimentally challenging. To this end, this contribution reports on the electrochemical generation of anions identical to intermediate structures and their spectroscopic characterization by in situ resonance Raman and UV/Vis spectroelectrochemistry and computational methods. Thereby, an efficient two‐electron pathway to the 4 H ‐imidazole electron‐accepting ligand is identified.