| Autor: |
Cantrill, Stuart J., Pease, Anthony R., Stoddart, J. Fraser |
| Zdroj: |
Journal of the Chemical Society, Dalton Transactions; November 7, 2000, Vol. 2000 Issue: 21 p3715-3734, 20p |
| Abstrakt: |
A range of secondary dialkylammonium (R2NH2+) ions has been shown to thread through the cavities of appropriately-sized crown ether compounds to afford interwoven complexes. X-Ray crystallographic investigations to probe the solid-state properties of these supermolecules have revealed that many subtle factorse.g., solvent of crystallisation, crown ether conformation and anion interactionscan influence the nature of the overall three-dimensional superstructures. Nonetheless, a family of building blocksnamely R2NH2+ ions and crown etherscan be generated, which constitute a molecular meccano kit. By mixing and matching these modules in different ways, intricate interwoven supramolecular architectures can be constructed. From relatively simple beginningswhere one R2NH2+ ion is threaded through one monotopic crown ether (dibenzo[24]crown-8)the designed evolution of the building blocks in the molecular meccano kit has led to more elaborate multiply encircled and/or multiply threaded superstructures. The effects of crown ether constitution, macroring size, and both crown ether as well as R2NH2+ ion substitution, upon the solid-state behaviour of these interwoven complexes have also been examined. A statistical analysis of the hydrogen bonding interactions observed in these systems has been carried out. It reveals that a reasonable correlation exists between N+H · · · O bond angle and H · · · O bond length. The correlation between CH · · · O bond angle and H · · · O distance is poor, suggesting that CH · · · O hydrogen bonding interactions are of secondary importance in determining the co-conformations adopted by these supermolecules. |
| Databáze: |
Supplemental Index |
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