Controlled synthesis and luminescence properties of trans-[Re6S8(CN)4(OH)2鈭?/sub>n(H2O)n]n鈭? octahedral rhenium(III) cluster units (n = 0, 1 or 2)
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- 作者：Alex ; ra Yu. Ledneva ; Konstantin A. Brylev ; Anton I. Smolentsev ; Yuri V. Mironov ; Yann Molard ; Stephane Cordier ; Noboru Kitamura ; Nikolay G. Naumov
- 关键词：Cluster ; Acid&ndash ; base dissociation ; Luminescence ; Crystal structure ; Rhenium
- 刊名：Polyhedron
- 出版年：8 January, 2014
- 年：2014
- 卷：67
- 期：Complete
- 页码：351-359
- 全文大小：1241 K
文摘
This work is devoted to the preparation of trans-[Re6S8(CN)4(OH)(H2O)]3鈭?/sup> and trans-[Re6S8(CN)4(H2O)2]2鈭?/sup> cluster complexes starting from trans-[Re6S8(CN)4(OH)2]4鈭?/sup> and a study of their luminescence properties. The controlled separation of each species could be achieved by pH adjustment: pH > 10, 5.5 < pH < 9 and pH < 3.5 for the dihydroxo trans-[Re6S8(CN)4(OH)2]4鈭?/sup>, aquahydroxo trans-[Re6S8(CN)4(OH)(H2O)]3鈭?/sup> and the diaqua trans-[Re6S8(CN)4(H2O)2]2鈭?/sup> complexes, respectively. The stepwise acid dissociation constants of trans-[Re6S8(CN)4(H2O)2]2鈭?/sup> were determined to be pKa1 = 3.3 and pKa2 = 6.6. Five novel compounds built up from the title cluster units were isolated and characterized: (Bu4N)4[Re6S8(CN)4(OH)2]路Bu4NOH (ass="boldFont">1), (Ph4P)3[Re6S8(CN)4(OH)(H2O)]路3.5H2O (ass="boldFont">2), (Bu4N)3[Re6S8(CN)4(OH)(H2O)]路2H2O (ass="boldFont">3), (Bu4N)2K[Re6S8(CN)4(OH)(H2O)]路6H2O (ass="boldFont">4) and (Bu4N)2[Re6S8(CN)4(H2O)2] (ass="boldFont">5). Compounds ass="boldFont">2, ass="boldFont">3 and ass="boldFont">4 were characterized by single-crystal X-ray diffraction analysis. For ass="boldFont">2 and ass="boldFont">3, it was found that the availability of the OH鈭?/sup> and H2O ligands in the trans-positions of the complex [Re6S8(CN)4(OH)(H2O)]3鈭?/sup> leads to the formation of intercluster bridging groups through strong hydrogen bonding. The trans disposition of the groups around Re6 enables the formation of polymeric linear chains of cluster complexes.