STRUCTURE AND REDOX PROPERTIES OF THE WATER-OXIDATION CATALYST [(BPY)2(OH2)RUORU(OH2)(BPY)2]4+
STRUCTURE AND REDOX PROPERTIES OF THE WATER-OXIDATION CATALYST [(BPY)2(OH2)RUORU(OH2)(BPY)2]4+
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DOI：
10.1021/ja00299a017
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发表时间：
1985-01-01
影响因子：
15
通讯作者：
MEYER, TJ
中科院分区：
文献类型：
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作者：
GILBERT, JA;EGGLESTON, DS;MEYER, TJ
水氧化催化剂µ-oxobis [aquabis（2，2，-bipyridine）ruthenium（III）]高氯酸盐二水合物[（bpy）2（OH）2 Ru 0 Ru（OH 2）（bpy）2]（C104）4·2 H20 [其中bpy为C10 H8 N2]的晶体和分子结构已由三维X射线计数器数据确定。该配合物属于单斜晶系，空间群为C2/c，晶胞尺寸为a= 22.712（9）nm，B= 13.189（4）nm，c= 20.084（5）nm，λ = 122.08（3）nm。基于2887个独立强度，结构已被细化至0.052的加权R因子值，其中f> 3（7）。结构表明，桥连Ru-O-Ru角为165.4，Ru-O键长为1.869（1）π。电化学研究表明，Ru！！1-朗姆酒二聚体经历初始单电子氧化为Rum-Rulv，并且由于两种氧化还原状态的酸碱性质，该对的电势具有复杂的pH依赖性。当pH高于2.2时，氧化为Runl-Rulv，然后是双电子氧化为[（bpy）2（0）RuIV 0 Ruv（0）（bpy）2] 3+，然后是不依赖于pH的单电子氧化为[（bpy）2（0）Ruv 0 Ruv（0）（bpy）2] 4+。在酸性高于2.2的溶液中，Rulv-Ruv对于歧化不稳定，并且Rum-RuIV二聚体氧化为[（bpy）2（0）Ruv 0 Ruv（0）（bpy）2] 4+通过三电子步骤发生。
The crystal and molecular structure of the water-oxidation catalyst µ-oxobis [aquabis (2, 2,-bipyridine) ruthenium (III)] perchlorate dihydrate,[(bpy) 2 (0H) 2Ru0Ru (0H2)(bpy) 2](C104) 4-2H20 [where bpy is C10H8N2], has been determined from three-dimensional X-ray counter data. The complex crystallizes in the monoclinic space group C2/c with four molecules in a cell of dimensions a= 22.712 (9) Á, b= 13.189 (4) Á, c= 20.084 (5) Á, ß= 122.08 (3). The structure has been refined to a value of the weighted R factor of 0.052 based on 2887 independent intensities with/> 3 (7). The structure shows that the bridging Ru-O-Ru angle is 165.4, the Ru-O bond lengths being 1.869 (1) Á. Electrochemical studies show that the Ru!! 1-Rum dimer undergoes an initial one-electron oxidation to Rum-Rulv and that the potentialof the couple has a complex pH dependence because of the acid-base properties of the two redox states. Above pH 2.2, oxidation to Runl-Rulv is followed by a two-electron oxidation to [(bpy) 2 (0) RuIV0Ruv (0)(bpy) 2] 3+ followedby a pH-independent, one-electron oxidation to [(bpy) 2 (0) Ruv0Ruv (0)(bpy) 2] 4+. In solutions more acidic than 2.2, Rulv-Ruv is unstable with respect to disproportionation, and oxidation of the Rum-RuIV dimer to [(bpy) 2 (0) Ruv0Ruv (0)(bpy) 2] 4+ occurs via a three-electron step.