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 2 II,II, were oxidized by 1 equiv in solution, leading to the mixed valence Ru 2 II,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 2 III,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 2 II,II and ligand to metal charge transfer (LMCT) type for Ru 2 III,II and Ru 2 III,III.
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 2 II,II, were oxidized by 1 equiv in solution, leading to the mixed valence Ru 2 II,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 2 III,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 2 II,II and ligand to metal charge transfer (LMCT) type for Ru 2 III,II and Ru 2 III,III.
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U2 - 10.1021/ic201668r
DO - 10.1021/ic201668r
M3 - Article
C2 - 22221281
AN - SCOPUS:84855393326
VL - 51
SP - 320
EP - 327
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 1
ER -