Ancillary Ligand Control of Electronic Structure in o-Benzoquinonediimine-Ruthenium Complex Redox Series: Structures, Electron Paramagnetic Resonance (EPR), and Ultraviolet−Visible−Near-Infrared (UV-vis-NIR) Spectroelectrochemistry
| Autor: | Goutam Kumar Lahiri, Sebastian Plebst, Shaikh M. Mobin, Wolfgang Kaim, Prabir Ghosh, Brigitte Schwederski, Ankita Das |
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| Rok vydání: | 2015 |
| Předmět: |
Excitation-Energies
Chemistry Ligand Diimines chemistry.chemical_element Ab-Initio Electronic structure Molecules Photochemistry Electrochemistry Redox law.invention Ruthenium Oxidative Dimerization Inorganic Chemistry Electron transfer Ultraviolet visible spectroscopy Density-Functional Theory 2-Phenylazopyridine law Iminothioquinone Physical and Theoretical Chemistry Acetylacetonate Electron paramagnetic resonance |
| Zdroj: | Inorganic Chemistry. 54:3376-3386 |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/ic503070j |
| Popis: | The compounds Ru(acac)2(Q) (1), [Ru(bpy)2(Q)](ClO4)2 ([2](ClO4)2), and [Ru(pap)2(Q)]PF6 ([3]PF6), containing Q = N,N'-diphenyl-o-benzoquinonediimine and donating 2,4-pentanedionate ligands (acac(-)), π-accepting 2,2(/)-bipyridine (bpy), or strongly π-accepting 2-phenylazopyridine (pap) were prepared and structurally identified. The electronic structures of the complexes and several accessible oxidized and reduced forms were studied experimentally (electrochemistry, magnetic resonance, ultraviolet-visible-near-infrared (UV-vis-NIR) spectroelectrochemistry) and computationally (DFT/TD-DFT) to reveal significantly variable electron transfer behavior and charge distribution. While the redox system 1(+)-1(-) prefers trivalent ruthenium with corresponding oxidation states Q(0)-Q(2-) of the noninnocent ligand, the series 2(2+)-2(0) and 3(2+)-3(-) retain Ru(II). The bpy and pap co-ligands are not only spectators but can also be reduced prior to a second reduction of Q. The present study with new experimental and computational evidence on the influence of co-ligands on the metal is complementary to a report on the substituent effects in o-quinonediimine ligands [Kalinina et al., Inorg. Chem. 2008, 47, 10110] and to the discussion of the most appropriate oxidation state formulation Ru(II)(Q(0)) or Ru(III)(Q(• -)). |
| Databáze: | OpenAIRE |
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