Electronic Structure of Anilinopyridinate-Supported Ru25+ Paddlewheel Compounds.
Inorg Chem
; 56(23): 14662-14670, 2017 Dec 04.
Article
em En
| MEDLINE
| ID: mdl-29140085
ABSTRACT
The electronic structures of the diruthenium compounds Ru2(ap)4Cl (1, ap = 2-anilinopyridinate) and Ru2(ap)4OTf (2) were investigated with UV-vis, resonance Raman, and magnetic circular dichroism (MCD) spectroscopies; SQUID magnetometry; and density functional theory (DFT) calculations. Both compounds have quartet spin ground states with large axial zero-field splitting of â¼60 cm-1 that is characteristic of Ru25+ compounds having a (π*, δ*)3 electron configuration and a Ru-Ru bond order of â¼2.5. Two major visible absorption features are observed at â¼770 and 430 nm in the electronic spectra, the assignments of which have previously been ambiguous. Both bands have significant charge-transfer character with some contributions from d â d transitions. MCD spectra were measured to enable the identification of d â d transitions that are not easily observable by UV-vis spectroscopy. In this way, we are able to identify bands due to δ â δ* and δ â π* transitions at â¼16â¯100 and 11â¯200-12â¯300 cm-1, respectively, the latter band being sensitive to the π-donating character of the axial ligand. The Ru-Ru stretches are coupled with pyridine rocking motions and give rise to observed resonance Raman peaks at â¼350 and 420 cm-1, respectively.
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Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article