Syntheses and redox properties of bis(hydroxoruthenium) complexes with quinone and bipyridine ligands. Water-oxidation catalysis

T. Wada; K. Tsuge; K. Tanaka

doi:10.1021/ic000552i

Syntheses and redox properties of bis(hydroxoruthenium) complexes with quinone and bipyridine ligands. Water-oxidation catalysis

T. Wada, K. Tsuge, K. Tanaka^*

^*Corresponding author for this work

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

178 Scopus citations

Abstract

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 [Ru^II₂(OH)₂(3.6-^tBu₂ qui)₂(btpyan)](SbF₆)₂ ([1](SbF₆)₂) results in the generation of [Ru^II₂(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 [Ru^II₂(O)₂(3,6-^t Bu₂sq)₂(btpyan)]⁰ undergoes ligand-localized oxidation at E_1/2= +0.40 V (vs Ag/AgCl) to give [Ru^II₂(O)₂(3,6-^t Bu₂qui)₂(btpyan)]²⁺ in MeOH solution, Furthermore, metal-localized oxidation of [Ru^II₂(O)₂(3,6-^t Bu₂qui)₂(btpyan)]²⁺ at E_p= +1.2 V in CF₃CH₂OH/ether or water gives [Ru^III₂(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 [Ru^II₂(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.

Original language	English
Pages (from-to)	329-337
Number of pages	9
Journal	Inorganic Chemistry
Volume	40
Issue number	2
DOIs	https://doi.org/10.1021/ic000552i
State	Published - 2001/01/15

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Physical and Theoretical Chemistry
Inorganic Chemistry

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@article{8a56b5c0a94e4bc1a85a5adf076b5fb4,

title = "Syntheses and redox properties of bis(hydroxoruthenium) complexes with quinone and bipyridine ligands. Water-oxidation catalysis",

abstract = "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-qu{\'i}) 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.",

author = "T. Wada and K. Tsuge and K. Tanaka",

year = "2001",

month = jan,

day = "15",

doi = "10.1021/ic000552i",

language = "英語",

volume = "40",

pages = "329--337",

journal = "Inorganic Chemistry",

issn = "0020-1669",

publisher = "American Chemical Society",

number = "2",

}

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 -

Syntheses and redox properties of bis(hydroxoruthenium) complexes with quinone and bipyridine ligands. Water-oxidation catalysis

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