Selenium−Manganese Carbonyl Clusters: Synthesis, Reversible Transformation, Electrochemical Properties, and Theoretical Calculations
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- 作者：Chia-Hua Ho ; Yen-Yi Chu ; Chien-Nan Lin ; Horng-Wen Chen ; Chung-Yi Huang ; Minghuey Shieh
- 刊名：Organometallics
- 出版年：2010
- 出版时间：October 11, 2010
- 年：2010
- 卷：29
- 期：19
- 页码：4396-4405
- 全文大小：1253K
- 年卷期：v.29,no.19(October 11, 2010)
- ISSN：1520-6041
文摘
The reaction of Se8 with 6 equiv of Mn2(CO)10 in concentrated KOH/MeOH solutions led to the formation of the odd-electron cluster [Se2Mn3(CO)9]2− (1), which was oxidized with [Cu(MeCN)4][BF4] to give the oxidation product [Se2Mn3(CO)9]− (2). Cluster 2 could be reconverted into cluster 1 by the addition of 4 M KOH/MeOH solutions in MeCN. While the trigonal-bipyramidal cluster 2 underwent cluster expansion to give rise to the large Se-inserted cluster [Se6Mn6(CO)18]4− (3) upon the reaction with a 1/8 equiv of Se8 in KOH/MeOH solutions, the square-pyramidal cluster 1 was transformed into the even larger Se-rich cluster [Se10Mn6(CO)18]4− (4) upon the addition of a 3/8 equiv of Se8 in MeOH. Cluster 3 underwent cluster expansion to form cluster 4 when treated with an additional 1/2 equiv of Se8 in MeCN. Conversely, cluster 4 was selectively reconverted into cluster 1 or 3 upon treatment with 4 or 2 equiv of Mn2(CO)10 in KOH/MeOH solutions, respectively. On the other hand, the Se6Mn6 cluster 3 was transformed into cluster 1 when treated with 2 equiv of Mn2(CO)10 in KOH/MeOH solutions. Furthermore, when cluster 3 was treated with [Cu(MeCN)4][BF4] or Mn(CO)5Br, cluster 2 and/or [Se5Mn4(CO)12]2− (5) were obtained. X-ray analysis showed that cluster 5 consisted of four Mn(CO)3 fragments, which were further connected by one μ3-Se and two μ3- and μ4-Se2 moieties to give a nest-like cluster. Moreover, Se10Mn6 cluster 4 could also be transformed into cluster 5 upon reaction with [Cu(MeCN)4][BF4] or Mn(CO)5Br. After a long reaction time, a new picnic-basket-like cluster, [Se4Mn3(CO)10]− (6), formed, which was also obtained from cluster 5 with [Cu(MeCN)4][BF4] or Mn(CO)5Br. Furthermore, the nature, cluster transformation and interconversion, and electrochemical properties of these Se−Mn−CO clusters were elucidated by molecular calculations at the B3PW91 level of the density functional theory.