Synthesis, Structures, and Spectroscopic, Magnetic, and Electrochemical Properties of (-Alkoxo)bis(
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- 作者：Tomoaki Tanase ; Yasuko Yamada ; Keiko Tanaka ; Tomoko Miyazu ; Masako Kato ; Keomil Lee ; Yoshikazu Sugihara ; Wasuke Mori ; Akio Ichimura ; Isamu Kinoshita ; Yasuhiro Yamamoto ; Masaaki Haga ; Yoichi Sasaki ; an
- 刊名：Inorganic Chemistry
- 出版年：1996
- 出版时间：October 9, 1996
- 年：1996
- 卷：35
- 期：21
- 页码：6230 - 6239
- 全文大小：271K
- 年卷期：v.35,no.21(October 9, 1996)
- ISSN：1520-510X
文摘
[RuCl2(dmso)4] (dmso =dimethyl sulfoxide) was treated with dhptaH5(1,3-diamino-2-hydroxypropanetetraaceticacid) and carboxylate ligands in the presence of NaOH or KOH and gavedinuclear ruthenium(III) complexes ofdhpta with two bridging carboxylates,M[Ru(dhpta)(
-O2CR)2](1, R = C6H5, M = Na;1', R = C6H5, M =K;2, R = p-OHC6H4, M =Na; 3, R =p-NH2C6H4, M = Na;4, R = CH3, M = Na; 4', R =CH3, M = K), whichwere characterized by elemental analysis, mass, electronic absorption,and 1H and 13C NMR spectroscopies,andX-ray absorption and crystallographic analyses (4,orthorhombic, space group Pca21 witha = 21.359(4) Å, b =7.484(2) Å, c = 12.930(2) Å, Z =4, R = 0.065, and Rw = 0.044 for1116 independent reflections with I >3
(I);4'·1.5H2O: monoclinic,P21, a = 7.689(2) Å,b = 17.213(2) Å, c = 18.103(2) Å,
= 94.50(1) 
, Z = 4, R=0.041, and Rw = 0.047 for 4705 independentreflections with I > 3(I)). Thecomplex anion consists of tworuthenium atoms bridged by the alkoxide of dhpta and the two acetateligands. The Ru-Ru distances of3.433(3) Å (4) and 3.421(1) Å (average)(4') are longer than those found in(-oxo)bis(-carboxylato)diruthenium(III) complexes. EXAFS analysis and 1H NMR spectraindicated that complexes 1-4 have the identicaldinuclearstructure in both solid and water solution states.Temperature-dependent magnetic susceptibility of1-4 showeda strong antiferromagnetic interaction between the two Ru(III)ions with -J = 310-470 cm-1.Cyclicvoltammograms showed two reduction processes at ca. -0.34 and ca.-0.94 V vs Ag/AgCl, corresponding totwo stepwise one-electron reductions,RuIIIRuIII 
RuIIIRuII RuIIRuII. The most remarkable featureis thelarge separation between the two redox potentials, implying that themixed-valence diruthenium(III,II) complexesof dhpta are fairly stable. Potentiostatic electrolysis of1-4 at a potential in betweenE11/2 andE21/2 consumed1 F per dimer and afforded a mixed-valence diruthenium species,[RuIIRuIII(dhpta)(-O2CR)2]2-,in solution,which showed two weak and broad absorption bands (
max5.5-5.7 and 11.6-11.9 kcm-1) in DMFassignable tointervalence charge transfer (IT) bands. The lower energy IT bandwas analyzed by Gaussian curve fitting andthe electron exchange integral Had was estimatedas 640-870 cm-1 on the basis of Hush'stheory. The spectroscopicanalysis indicated that[RuIIRuIII(dhpta)(O2CR)2]2-belongs to Class II type mixed-valence dirutheniumcomplexes.
-O2CR)2](1, R = C6H5, M = Na;1', R = C6H5, M =K;2, R = p-OHC6H4, M =Na; 3, R =p-NH2C6H4, M = Na;4, R = CH3, M = Na; 4', R =CH3, M = K), whichwere characterized by elemental analysis, mass, electronic absorption,and 1H and 13C NMR spectroscopies,andX-ray absorption and crystallographic analyses (4,orthorhombic, space group Pca21 witha = 21.359(4) Å, b =7.484(2) Å, c = 12.930(2) Å, Z =4, R = 0.065, and Rw = 0.044 for1116 independent reflections with I >3(I);4'·1.5H2O: monoclinic,P21, a = 7.689(2) Å,b = 17.213(2) Å, c = 18.103(2) Å, = 94.50(1) , Z = 4, R=0.041, and Rw = 0.047 for 4705 independentreflections with I > 3(I)). Thecomplex anion consists of tworuthenium atoms bridged by the alkoxide of dhpta and the two acetateligands. The Ru-Ru distances of3.433(3) Å (4) and 3.421(1) Å (average)(4') are longer than those found in(-oxo)bis(-carboxylato)diruthenium(III) complexes. EXAFS analysis and 1H NMR spectraindicated that complexes 1-4 have the identicaldinuclearstructure in both solid and water solution states.Temperature-dependent magnetic susceptibility of1-4 showeda strong antiferromagnetic interaction between the two Ru(III)ions with -J = 310-470 cm-1.Cyclicvoltammograms showed two reduction processes at ca. -0.34 and ca.-0.94 V vs Ag/AgCl, corresponding totwo stepwise one-electron reductions,RuIIIRuIII RuIIIRuII RuIIRuII. The most remarkable featureis thelarge separation between the two redox potentials, implying that themixed-valence diruthenium(III,II) complexesof dhpta are fairly stable. Potentiostatic electrolysis of1-4 at a potential in betweenE11/2 andE21/2 consumed1 F per dimer and afforded a mixed-valence diruthenium species,[RuIIRuIII(dhpta)(-O2CR)2]2-,in solution,which showed two weak and broad absorption bands (max5.5-5.7 and 11.6-11.9 kcm-1) in DMFassignable tointervalence charge transfer (IT) bands. The lower energy IT bandwas analyzed by Gaussian curve fitting andthe electron exchange integral Had was estimatedas 640-870 cm-1 on the basis of Hush'stheory. The spectroscopicanalysis indicated that[RuIIRuIII(dhpta)(O2CR)2]2-belongs to Class II type mixed-valence dirutheniumcomplexes.