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Updated: May 30, 2026
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Probing intermetallic coupling in dinuclear N-heterocyclic carbene ruthenium(II) complexes
Laszlo Mercs1, Antonia Neels, Helen Stoeckli-Evans
1Department of Chemistry, University of Fribourg, Chemin du Musee 9, CH-1700 Fribourg, Switzerland.
Abstract:
A series of bimetallic N-heterocyclic carbene (NHC) ruthenium(II) complexes were synthesized, which comprise two [RuCl(2)(cymene)(NHC)] units that are interlinked via the NHC nitrogens by alkyl chains of different length. Electrochemical characterization revealed two mutually dependent oxidation processes for the complex with a methylene linker, indicating moderate intramolecular electronic coupling of the two metal centers (class II system). The degree of coupling decreases rapidly upon increasing the number of CH(2) units in the linker and provides essentially decoupled class I species when propylene or butylene linkers are used. Electrochemical analyses combined with structural investigations suggest a through-bond electronic coupling. Replacement of the alkyl linker with a p-phenylene group afforded cyclometalated complexes, which were considerably less stable. The electronic coupling in the methylene-linked complex and the relatively robust NHC-ruthenium bond may provide access to species that are switchable on the molecular scale.
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