π-Stacking attraction vs. electrostatic repulsion: competing supramolecular interactions in a tpphz-bridged Ru(II)/Au(III) complex

Language
en
Document Type
Article
Issue Date
2018-01-17
Issue Year
2016
Authors
Sorsche, Dieter
Schaub, Markus
Heinemann, Frank W.
Habermehl, Johannes
Kuhri, Susanne
Guldi, Dirk
Guthmuller, Julien
Rau, Sven
Editor
Abstract

The synthesis and characterization of a mixed metal ruthenium(II)/gold(III) complex bridged by tetrapyridophenazine (tpphz) are described. It is isostructural and isoelectronic to the well-known photocatalysts with palladium(II) or platinum(II). Concentration dependent 1H-NMR spectroscopy and XRD studies show that the electrostatic repulsion between the gold(III) moieties exceeds the attractive π-stacking interaction. Theoretical calculations based on the new structural data confirm an increased positive charge on the bridging ligand as well as significantly altered orbital symmetry as compared to the previously investigated palladium(II) complex. This is the first example of a tpphz ruthenium(II) complex where π-stacking is completely inhibited. The detailed investigation of the solid-state structure showed for the first time in bimetallic tpphz bridged complexes no significant torsion within the bridging ligand itself. Although catalytic performance for proton reduction by gold(III) is naturally not observed, its photochemical decomposition in colloidal gold particles could be shown by TEM and DLS.

Journal Title
Dalton Transactions
Volume
45
Issue
32
Citation

Dalton Transactions 45.32 (2016): S. 12846-12853. http://pubs.rsc.org/en/content/articlelanding/2016/dt/c6dt01643j

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