An odd-electron complex [Ru(k)(NO(m))(Q(n))(terpy)]2+ with two prototypical non-innocent ligands
Atanu Kumar Das1, Biprajit Sarkar, Carole Duboc
1Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70550 Stuttgart, Germany.
Angewandte Chemie (International Ed. in English)
|May 12, 2009
Summary
The paramagnetic ruthenium complex exists as an iminosemiquinone radical. This structure was confirmed using X-ray diffraction, spectroscopy, and DFT calculations.
Area of Science:
- Coordination chemistry
- Inorganic chemistry
- Spectroscopy
Background:
- Paramagnetic metal complexes can exhibit diverse electronic structures.
- Understanding the precise oxidation states and radical character is crucial for predicting reactivity and properties.
Purpose of the Study:
- To elucidate the electronic structure and oxidation states of a paramagnetic ruthenium complex.
- To determine the specific radical species formed within the complex.
Main Methods:
- Single-crystal X-ray diffraction for structural determination.
- Infrared (IR) and Electron Paramagnetic Resonance (EPR) spectroscopy (conventional and high frequency) for electronic characterization.
- Density Functional Theory (DFT) calculations for theoretical validation.
Main Results:
- Six possible oxidation state combinations were considered.
- Experimental and computational data converged to identify the iminosemiquinone radical structure.
- The complex is definitively characterized as [Ru(II)(NO(I))(iminosemiquinone(I-))(terpy)](2+).
Conclusions:
- The paramagnetic title complex adopts an iminosemiquinone radical configuration.
- This finding clarifies the electronic ground state of the ruthenium complex, impacting its chemical behavior.
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