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In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions
Published on: June 16, 2014
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Communication: Does a single CH3CN molecule attached to Ru(bipy)3(2+) affect its absorption spectrum?
M H Stockett1, S Brøndsted Nielsen1
1Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
The Journal of Chemical Physics
|May 10, 2015
Summary
The photophysics of Tris(bipyridine)ruthenium(II) reveal that solvent molecules, not just one, are needed to localize its excited state. This finding clarifies the delocalized nature of its metal-to-ligand charge transfer transition.
Area of Science:
- Photochemistry
- Coordination Chemistry
- Spectroscopy
Background:
- Tris(bipyridine)ruthenium(II) (Ru(bipy)3 (2+)) is a key transition metal complex.
- Its metal-to-ligand charge transfer (MLCT) transition is responsible for its color.
- Debate exists on whether the MLCT state is delocalized or localized.
Purpose of the Study:
- To investigate the delocalization of the MLCT state in Ru(bipy)3 (2+).
- To determine the role of solvent molecules in localizing the MLCT excited state.
- To understand the factors influencing the photophysical properties of Ru(bipy)3 (2+).
Main Methods:
- Gas-phase action spectroscopy was employed.
- Absorption spectra of bare Ru(bipy)3 (2+) ions were measured.
- Spectra were compared with those of complexes solvated by acetonitrile molecules.
Main Results:
- A single acetonitrile molecule did not alter the absorption spectrum, indicating a delocalized state.
- Gas-phase spectra (bare and mono-solvated) were blueshifted compared to bulk solution spectra.
- This blueshift suggests solvent polarizability localizes the MLCT state in solution.
Conclusions:
- The MLCT excited state of Ru(bipy)3 (2+) is delocalized in the absence of significant solvent interaction.
- Multiple solvent molecules are required to break the symmetry and localize the MLCT state.
- Solvent-induced localization is crucial for reproducing solution-phase photophysical characteristics.
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