Ancillary ligand determination of the spin location in both oxidised and reduced forms of diruthenium complexes bridged by bis-bidentate 1,4-bis(2-phenolato)-1,4-diazabutadiene
| Autor: | Jan Fiedler, Biprajit Sarkar, Markus Leboschka, Sanjib Kar, Wolfgang Kaim, Sandeep Ghumaan, Goutam Kumar Lahiri |
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| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
Denticity
Stereochemistry Spectroelectrochemical Properties Electronic structure Redox Electronic-Structure Spectral line law.invention Inorganic Chemistry Metal Electron transfer law Oxidation Electron paramagnetic resonance States Chemistry Ru Redox Series Non-innocent ligand Stabilization Crystallography Ruthenium Complexes visual_art Coordination visual_art.visual_art_medium Metal-Complexes |
| Zdroj: | IndraStra Global. |
| ISSN: | 2381-3652 |
| Popis: | The rare bridging mode of 1,4-bis(2-phenolato)-1,4-diazabutadiene = glyoxalbis(2-hydroxyanil) (L2-) is adopted in {(mu-L2-)[Ru-II(bpy)(2)](2)}(2+) (1(2+)), obtained as bis-perchlorate. Four well accessible redox forms of 1(n) (n = 4+, 3+, 2+, +) have been characterised by UV-VIS-NIR spectroelectrochemistry. The (3+) and (+) intermediates have also been investigated by EPR, both showing radical-type signals close to g = 2. This observation stands in stark contrast to EPR results previously obtained for the related {(mu-L)[Ru(acac)(2)](2)}(n), n = + and -, both of which exhibit metal-centred spin. In combination with the UV-VIS-NIR spectra these results suggest the preferential involvement of the multistep ligand redox system Ln- in the electron transfer processes. The relative stabilisation of Ru-II by pi-accepting bpy is made responsible for the oxidation of the ligand L2- instead of the metal. |
| Databáze: | OpenAIRE |
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