Synthesis of isomeric B-methylated tantalum carboranes, (Me2N)3TaC2B9H10Me
Synthesis of isomeric B-methylated tantalum carboranes, (Me2N)3TaC2B9H10Me
复制标题
异构 B-甲基化钽碳硼烷 (Me2N)3TaC2B9H10Me 的合成
DOI：
10.1039/b103353k
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
D. Yufit
中科院分区：
文献类型：
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作者：
M. A. Fox;J. Howard;A. K. Hughes;J. M. Malget;D. Yufit
笼形烷基化金属碳硼烷配合物[4,4,4-(NMe2)3-3- me -4,1,2- close - tac2b9h10] 8是Ta(NMe2)5与nido-11- me -2,7- c2b9h24反应的唯一产物，该配合物在碱性条件下容易发生骨架重排。没有重排的发生，说明水解氨解反应是一种干净的合成方法。由Ta(NMe2)5与[Me3NH][nido-9- me -7,8- c2b9h11] 5和[Me3NH][nido-8- me -7,9- c2b9h11] 6反应，分别生成了金属碳硼烷[3,3,3-(NMe2)3-4- me -3,1,2-closo- tac2b9h10] 9和[2,2,2-(NMe2)3-3- me -2,1,7-closo- tac2b9h10] 10。通过详细的多核（11B、13C和1H） NMR谱分析，推导出金属碳硼烷8、9和10的性质。这些几何结构得到了硼核磁共振位移预测的支持，该预测基于已知的非甲基化类似物[3,3,3-(NMe2)3-closo-3,1,2- tac2b9h10] 1和[3,3,3-(NMe2)3-closo-3,1,2- tac2b9h10] 2的位移和b -甲基碳硼烷closo-3- me -1,2- c2b10h1111, 4- me -1,2- c2b10h1112和2- me -1,7- c2b10h1113的计算位移（GIAO-B3LYP/6-311G*//MP2/6-31G*）。用x射线衍射测定了8的分子结构。
The cage-alkylated metallacarborane complex [4,4,4-(NMe2)3-3-Me-4,1,2-closo-TaC2B9H10] 8, is obtained as the only product from the reaction of Ta(NMe2)5 with nido-11-Me-2,7-C2B9H124, which is prone to skeletal rearrangement under basic conditions. That no rearrangement occurs indicates that the hydroamminolysis reaction is a clean synthetic method. The isomeric metallacarboranes [3,3,3-(NMe2)3-4-Me-3,1,2-closo-TaC2B9H10] 9 and [2,2,2-(NMe2)3-3-Me-2,1,7-closo-TaC2B9H10] 10 are produced from the reaction of Ta(NMe2)5 with [Me3NH][nido-9-Me-7,8-C2B9H11] 5 and [Me3NH][nido-8-Me-7,9-C2B9H11] 6 respectively. Identities of the metallacarboranes 8, 9 and 10 are deduced by detailed multinuclear (11B, 13C and 1H) NMR spectroscopy. These geometries are supported by boron NMR shift predictions based on observed shifts of the known non-methylated analogues [3,3,3-(NMe2)3-closo-3,1,2-TaC2B9H10] 1 and [3,3,3-(NMe2)3-closo-3,1,2-TaC2B9H10] 2 and calculated shifts (GIAO-B3LYP/6-311G*//MP2/6-31G*) of the B-methyl carboranes, closo-3-Me-1,2-C2B10H1111, 4-Me-1,2-C2B10H1112 and 2-Me-1,7-C2B10H1113. The molecular structure of 8 has been determined by X-ray diffraction.