Aggregation Patterns in ,'-Stabilized Carbanions: Assembly of a
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- 作者：Kenneth W. Henderson ; Alan R. Kennedy ; and Dugald J. MacDougall
- 刊名：Inorganic Chemistry
- 出版年：2003
- 出版时间：April 21, 2003
- 年：2003
- 卷：42
- 期：8
- 页码：2736 - 2741
- 全文大小：129K
- 年卷期：v.42,no.8(April 21, 2003)
- ISSN：1520-510X
文摘
The 
,'-stabilized carbanion complexes [PhSO2CHCNNa·THF], 3, [t-BuSO2CHCNNa], 4, [PhSO2CHCNK], 5,[t-BuSO2CHCNK], 6, and [MeSO2CHCNLi·TMEDA], 7, have been synthesized via the metalation of the parent(organo)sulfonylacetonitriles by BuLi, BuNa, or BnK in THF solution (or THF/TMEDA in the case of 7). In addition,complexes 3 and 7 have been characterized by single-crystal X-ray analyses and have been found to adopt relatedstructures in the solid state. Complex 7 is a molecular dimer containing a central 12-membered (OSCCNLi)2 ringcore, with each metal rendered tetracoordinate by binding to a chelating TMEDA molecule. As found in relatedcomplexes, no direct carbanion to lithium contacts are present in the structure of 7. Complex 3 forms a polymericcage structure composed of associated "dimeric" (OSCCNNa)2 rings, similar to those found in 7. The larger sodiumcations, and the presence of only one THF molecule/metal, allow additional contacts with the anions, leading tohexacoordination at the metal centers. These contacts include long-range transannular Na-N interactions (2.8042(14)Å) across the central dimeric ring and "interdimer" Na-C connections (2.8718(15) Å). Dissolution of complexes3-6 and their lithiated derivatives [PhSO2CHCNLi·TMEDA], 1, and [t-BuSO2CHCNLi·THF], 2, in DMSO-d6 resultsin almost identical chemical shifts for each type of ligand. This suggests that charge-separated complexes of theform [RSO2CHCN]-[M(DMSO-d6)n]+ are formed in highly polar solution.
,'-stabilized carbanion complexes [PhSO2CHCNNa·THF], 3, [t-BuSO2CHCNNa], 4, [PhSO2CHCNK], 5,[t-BuSO2CHCNK], 6, and [MeSO2CHCNLi·TMEDA], 7, have been synthesized via the metalation of the parent(organo)sulfonylacetonitriles by BuLi, BuNa, or BnK in THF solution (or THF/TMEDA in the case of 7). In addition,complexes 3 and 7 have been characterized by single-crystal X-ray analyses and have been found to adopt relatedstructures in the solid state. Complex 7 is a molecular dimer containing a central 12-membered (OSCCNLi)2 ringcore, with each metal rendered tetracoordinate by binding to a chelating TMEDA molecule. As found in relatedcomplexes, no direct carbanion to lithium contacts are present in the structure of 7. Complex 3 forms a polymericcage structure composed of associated "dimeric" (OSCCNNa)2 rings, similar to those found in 7. The larger sodiumcations, and the presence of only one THF molecule/metal, allow additional contacts with the anions, leading tohexacoordination at the metal centers. These contacts include long-range transannular Na-N interactions (2.8042(14)Å) across the central dimeric ring and "interdimer" Na-C connections (2.8718(15) Å). Dissolution of complexes3-6 and their lithiated derivatives [PhSO2CHCNLi·TMEDA], 1, and [t-BuSO2CHCNLi·THF], 2, in DMSO-d6 resultsin almost identical chemical shifts for each type of ligand. This suggests that charge-separated complexes of theform [RSO2CHCN]-[M(DMSO-d6)n]+ are formed in highly polar solution.