TY - JOUR
T1 - Characterization of a stable ruthenium complex with an oxyl radical
AU - Kobayashi, Katsuaki
AU - Ohtsu, Hideki
AU - Wada, Tohru
AU - Kato, Tatsuhisa
AU - Tanaka, Koji
PY - 2003/6/4
Y1 - 2003/6/4
N2 - The ruthenium oxyl radical complex, [RuII(trpy)(Bu2SQ)O·-] 2,2′:6′,2″-terpyridine, Bu2-SQ = 3,5-di-tert-butyl-1,2-benzosemiquinone) was prepared for the first time by the double deprotonation of the aqua ligand of [RuIII(trpy)(Bu2SQ)(OH2)] (ClO4)2. [RuIII(trpy)(Bu2SQ)(OH2)] (ClO4O2 is reversibly converted to [RuIII(trpy)(Bu2SQ)(OH-)]+ upon dissociation of the aqua proton (pKa 5.5). Deprotonation of the hydroxo proton gave rise to intramolecular electron transfer from the resultant O2- to Ru-dioxolene. The resultant [RuII(trpy)(Bu2SQ)O·-] showed antiferromagnetic behavior with a Rull-semiquinone moiety and oxyl radical, the latter of which was characterized by a spin trapping technique. The most characteristic structural feature of [RuII(trpy)(Bu2SQ)O·-] is a long Ru-O bond length (2.042(6) Å) as the first terminal metal-O bond with a single bond length. To elucidate the substituent effect of a quinone ligand, [RuIII(trpy)(4ClSQ)(OH2)]- (ClO4)2 (4ClSQ = 4-chloro-1,2-benzosemiquinone) was prepared and we compared the deprotonation behavior of the aqua ligand with that of [RuIII(trpy)(Bu2SQ)(OH2)] (ClO4)2. Deprotonation of the aqua ligand of [RuIII(trpy)(4ClSQ)(OH2)](ClO4)2 induced intramolecular electron transfer from OH- to the [RuIII-(4ClSQ)] moiety affording [RuII(trpy)(4ClSQ)(OH·)]+, which then probably changed to [RuII(trpy)(4ClSQ)O·-]. The antiferromagnetic interactions (J values) between RuII-semiquinone and the oxyl radical for [RuII(trpy)(Bu2SQ)O·-] and for [RuII(trpy)(4ClSQ)O·-] were 2J = -0.67 cm-1 and -1.97 cm-1, respectively.
AB - The ruthenium oxyl radical complex, [RuII(trpy)(Bu2SQ)O·-] 2,2′:6′,2″-terpyridine, Bu2-SQ = 3,5-di-tert-butyl-1,2-benzosemiquinone) was prepared for the first time by the double deprotonation of the aqua ligand of [RuIII(trpy)(Bu2SQ)(OH2)] (ClO4)2. [RuIII(trpy)(Bu2SQ)(OH2)] (ClO4O2 is reversibly converted to [RuIII(trpy)(Bu2SQ)(OH-)]+ upon dissociation of the aqua proton (pKa 5.5). Deprotonation of the hydroxo proton gave rise to intramolecular electron transfer from the resultant O2- to Ru-dioxolene. The resultant [RuII(trpy)(Bu2SQ)O·-] showed antiferromagnetic behavior with a Rull-semiquinone moiety and oxyl radical, the latter of which was characterized by a spin trapping technique. The most characteristic structural feature of [RuII(trpy)(Bu2SQ)O·-] is a long Ru-O bond length (2.042(6) Å) as the first terminal metal-O bond with a single bond length. To elucidate the substituent effect of a quinone ligand, [RuIII(trpy)(4ClSQ)(OH2)]- (ClO4)2 (4ClSQ = 4-chloro-1,2-benzosemiquinone) was prepared and we compared the deprotonation behavior of the aqua ligand with that of [RuIII(trpy)(Bu2SQ)(OH2)] (ClO4)2. Deprotonation of the aqua ligand of [RuIII(trpy)(4ClSQ)(OH2)](ClO4)2 induced intramolecular electron transfer from OH- to the [RuIII-(4ClSQ)] moiety affording [RuII(trpy)(4ClSQ)(OH·)]+, which then probably changed to [RuII(trpy)(4ClSQ)O·-]. The antiferromagnetic interactions (J values) between RuII-semiquinone and the oxyl radical for [RuII(trpy)(Bu2SQ)O·-] and for [RuII(trpy)(4ClSQ)O·-] were 2J = -0.67 cm-1 and -1.97 cm-1, respectively.
UR - http://www.scopus.com/inward/record.url?scp=0038547869&partnerID=8YFLogxK
U2 - 10.1021/ja0211510
DO - 10.1021/ja0211510
M3 - 学術論文
C2 - 12769583
AN - SCOPUS:0038547869
SN - 0002-7863
VL - 125
SP - 6729
EP - 6739
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 22
ER -