Π-Stacking attraction vs. electrostatic repulsion: competing supramolecular interactions in a tpphz-bridged Ru(ii)/Au(iii) complex. Issue 32 (29th July 2016)

• Record Type: Journal Article
• Authors: Sorsche, Dieter; Schaub, Markus; Heinemann, Frank W.; Habermehl, Johannes; Kuhri, Susanne; Guldi, Dirk; Guthmuller, Julien; Rau, Sven
• Is Part Of: Dalton transactions. Volume 45:Issue 32(2016)
• Page Start: 12846
• Page End: 12853
• Publication Date: 2016-07-29
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c6dt01643j
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Electrostatic repulsion between gold(iii ) coordination spheres exceeds π-stacking for the first time in a tpphz-bridged dinuclear PMD model complex. 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 1 H-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.