TY - JOUR
T1 - Synthesis, structure, and electronic properties of RuN 6 dinuclear Ru-Hbpp complexes
AU - Roeser, Stephan
AU - Ertem, Mehmed Z.
AU - Cady, Clyde
AU - Lomoth, Rainer
AU - Benet-Buchholz, Jordi
AU - Hammarström, Leif
AU - Sarkar, Biprajit
AU - Kaim, Wolfgang
AU - Cramer, Christopher J.
AU - Llobet, Antoni
PY - 2012/1/2
Y1 - 2012/1/2
N2 - A series of RuN 6 dinuclear Ru-Hbpp complexes (Hbpp is the dinucleating tetraaza ligand 3,5-bis(pyridyl)pyrazole) of general formula {[Ru II(R 2-trpy)(MeCN)] 2(μ-R 1-bpp)} 3+, 10 3+-14 3+, (R 1 = H, Me, or NO 2. and R 2 = H, Me, MeO; see Scheme 1) has been prepared from their Cl - or AcO - bridged precursors. The complexes have been characterized by UV-vis, NMR, CV, and some by X-ray. Complexes 10 3+-14 3+, Ru 2II,II, were oxidized by 1 equiv in solution, leading to the mixed valence Ru 2II,III complexes 10 4+-14 4+ containing one unpaired electron and were characterized by EPR and UV-vis-near-IR, which showed metal-centered spin and the presence of low-energy IVCT bands. The H ab parameter indicates a relatively strong electronic coupling between the two ruthenium centers (class II). Further two electron oxidation in solution of the 10 3+-14 3+ led to the formation of EPR silent Ru 2III,III complexes 10 5+-14 5+, that were further characterized by UV-vis-NIR. TD-DFT calculations are employed to assign the nature of the UV-vis transitions for the complexes in the various oxidation states, which are of metal to ligand charge transfer (MLCT) type for Ru 2II,II and ligand to metal charge transfer (LMCT) type for Ru 2III,II and Ru 2III,III. © 2011 American Chemical Society.
AB - A series of RuN 6 dinuclear Ru-Hbpp complexes (Hbpp is the dinucleating tetraaza ligand 3,5-bis(pyridyl)pyrazole) of general formula {[Ru II(R 2-trpy)(MeCN)] 2(μ-R 1-bpp)} 3+, 10 3+-14 3+, (R 1 = H, Me, or NO 2. and R 2 = H, Me, MeO; see Scheme 1) has been prepared from their Cl - or AcO - bridged precursors. The complexes have been characterized by UV-vis, NMR, CV, and some by X-ray. Complexes 10 3+-14 3+, Ru 2II,II, were oxidized by 1 equiv in solution, leading to the mixed valence Ru 2II,III complexes 10 4+-14 4+ containing one unpaired electron and were characterized by EPR and UV-vis-near-IR, which showed metal-centered spin and the presence of low-energy IVCT bands. The H ab parameter indicates a relatively strong electronic coupling between the two ruthenium centers (class II). Further two electron oxidation in solution of the 10 3+-14 3+ led to the formation of EPR silent Ru 2III,III complexes 10 5+-14 5+, that were further characterized by UV-vis-NIR. TD-DFT calculations are employed to assign the nature of the UV-vis transitions for the complexes in the various oxidation states, which are of metal to ligand charge transfer (MLCT) type for Ru 2II,II and ligand to metal charge transfer (LMCT) type for Ru 2III,II and Ru 2III,III. © 2011 American Chemical Society.
U2 - 10.1021/ic201668r
DO - 10.1021/ic201668r
M3 - Article
SN - 0020-1669
VL - 51
SP - 320
EP - 327
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 1
ER -