Peer-Reviewed Journal Details
Mandatory Fields
Brady, I;Leane, D;Hughes, HP;Forster, RJ;Keyes, TE
2004
January
Dalton Transactions
Electronic properties of Ru(II) complexes bound to a bisphenolate bridge with low lying pi* orbitals
Published
14 ()
Optional Fields
RUTHENIUM(II) COMPLEXES RESONANCE RAMAN LIGANDS REDOX STATE LOCATION OSMIUM SERIES
334
341
The synthesis and a detailed investigation into the electronic properties of mononuclear and dinuclear Ru(II) complexes of the ligand bis(2-hydroxyphenyl)-2,5-dihydropyrazine (H2BHD) is described. In these complexes the Ru(II) moieties are bound through O,N coordination to an anionic phenolate and the pyrazine bridge. Relatively few reports are available on the dinuclear complexes bridged across a phenolate and this study provides an opportunity to examine the impact of reduced oxygen donor ligands on metal-metal communication. The results presented here reveal some very unusual behavior whereby the apparent location of the LUMO changes between the mononuclear and dinuclear complexes. The lowest energy optical transition appears to involve the peripheral bipyridine ligand as acceptor in the mononuclear complex, whereas this ligand is not involved in the lowest energy optical transition in the dinuclear complex. The origin of this difference is not clear, however, significant changes in the electronic properties of the mononuclear complex are observed on coordination of the second metal, reflected in significant alterations in the electrochemistry of the bridge and metals as well as changes in the optical spectroscopy. The BHD2- bridge is shown to support weakly coupled class II behavior according to the Robin and Day classification, reflected in a K-c of 335.
CAMBRIDGE
1477-9226
10.1039/b312641b
Grant Details