TY - JOUR
T1 - Syntheses and redox properties of bis(hydroxoruthenium) complexes with quinone and bipyridine ligands. Water-oxidation catalysis
AU - Wada, T.
AU - Tsuge, K.
AU - Tanaka, K.
PY - 2001/1/15
Y1 - 2001/1/15
N2 - The novel bridging ligand 1,8-bis(2,2′;6′,2″-terpyridyl)anthracene (btpyan) is synthesized by three reactions from 1,8-diformylanthracene to connect two [Ru(L)(OH)]+ units (L = 3,6-di-tert-buty1-1,2-benzoquinone (3,6-tBu2-quí) and 2.2′-bipyridine (bpy)). An addition of tBuOK (2.0 equiv) to a methanolic solution of [RuII2(OH)2(3.6-tBu2 qui)2(btpyan)](SbF6)2 ([1](SbF6)2) results in the generation of [RuII2(O)2(3,6-t Bu2sq)2(btpyan)]0 (3,6-tBu2sq = 3,6-di-tert-butyl-1,2-semiquinone) due to the reduction of quinone coupled with the dissociation of the hydroxo protons. The resultant complex [RuII2(O)2(3,6-t Bu2sq)2(btpyan)]0 undergoes ligand-localized oxidation at E1/2= +0.40 V (vs Ag/AgCl) to give [RuII2(O)2(3,6-t Bu2qui)2(btpyan)]2+ in MeOH solution, Furthermore, metal-localized oxidation of [RuII2(O)2(3,6-t Bu2qui)2(btpyan)]2+ at Ep= +1.2 V in CF3CH2OH/ether or water gives [RuIII2(O)2(3,6-t Bu2qui)2(btpyan)]4+, which catalyzes water oxidation. Controlled-potential electrolysis of [1](SbF6)2 at +1.70 V in the presence of H2O in CF3CH2OH evolves dioxygen with a current efficiency of 91% (21 turnovers). The turnover number of O2 evolution increases to 33 500 when the electrolysis is conducted in water (pH 4.0) by using a [1](SbF6)2-modified ITO electrode. On the other hand, the analogous complex [RuII2(OH)2(bpy)2(btpyan)]- (SbF6)2 ([2](SBF6)2) shows neither dissociation of the hydroxo protons, even in the presence of a large excess of tBuOK, nor activity for the oxidation of H2O under similar conditions.
AB - The novel bridging ligand 1,8-bis(2,2′;6′,2″-terpyridyl)anthracene (btpyan) is synthesized by three reactions from 1,8-diformylanthracene to connect two [Ru(L)(OH)]+ units (L = 3,6-di-tert-buty1-1,2-benzoquinone (3,6-tBu2-quí) and 2.2′-bipyridine (bpy)). An addition of tBuOK (2.0 equiv) to a methanolic solution of [RuII2(OH)2(3.6-tBu2 qui)2(btpyan)](SbF6)2 ([1](SbF6)2) results in the generation of [RuII2(O)2(3,6-t Bu2sq)2(btpyan)]0 (3,6-tBu2sq = 3,6-di-tert-butyl-1,2-semiquinone) due to the reduction of quinone coupled with the dissociation of the hydroxo protons. The resultant complex [RuII2(O)2(3,6-t Bu2sq)2(btpyan)]0 undergoes ligand-localized oxidation at E1/2= +0.40 V (vs Ag/AgCl) to give [RuII2(O)2(3,6-t Bu2qui)2(btpyan)]2+ in MeOH solution, Furthermore, metal-localized oxidation of [RuII2(O)2(3,6-t Bu2qui)2(btpyan)]2+ at Ep= +1.2 V in CF3CH2OH/ether or water gives [RuIII2(O)2(3,6-t Bu2qui)2(btpyan)]4+, which catalyzes water oxidation. Controlled-potential electrolysis of [1](SbF6)2 at +1.70 V in the presence of H2O in CF3CH2OH evolves dioxygen with a current efficiency of 91% (21 turnovers). The turnover number of O2 evolution increases to 33 500 when the electrolysis is conducted in water (pH 4.0) by using a [1](SbF6)2-modified ITO electrode. On the other hand, the analogous complex [RuII2(OH)2(bpy)2(btpyan)]- (SbF6)2 ([2](SBF6)2) shows neither dissociation of the hydroxo protons, even in the presence of a large excess of tBuOK, nor activity for the oxidation of H2O under similar conditions.
UR - http://www.scopus.com/inward/record.url?scp=0035862659&partnerID=8YFLogxK
U2 - 10.1021/ic000552i
DO - 10.1021/ic000552i
M3 - 学術論文
C2 - 11170540
AN - SCOPUS:0035862659
SN - 0020-1669
VL - 40
SP - 329
EP - 337
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 2
ER -