Cation-ether complexes in the gas phase: thermodynamic insight into molecular recognition
Cation-ether complexes in the gas phase: thermodynamic insight into molecular recognition
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DOI：
10.1016/s1387-3806(99)00165-7
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发表时间：
1999-12-20
影响因子：
1.8
通讯作者：
Armentrout, PB
中科院分区：
文献类型：
--
作者：
Armentrout, PB
讨论了碱金属阳离子Li+， Na+, K+， Rb+和Cs+与一系列醚，1-4二甲基醚，1和2二甲氧基乙烷以及12c4, 15c5和18c6冠醚结合的键解离能的变化趋势。在以前的研究中，通过分析氙对阳离子-醚配合物的碰撞诱导离解的阈值来确定键能，该阈值是在引导离子束串联质谱仪中测量的。对数据分析的细节进行了审查，并通过与文献中的理论结果进行比较确定了结果的准确性。结合实验和理论结果，为金属冠配合物的评价提供了广泛的热化学数据库，这是分子识别的一个简单例子。这些结果表明优化金属-氧键距离和氧对金属的局部偶极子取向的重要性。此外，研究表明，这些配合物的激发态构象可能在几个系统中被观察到，这是配合物形成过程中有趣的金属依赖动力学的结果。(C) 1999 Elsevier Science B.V.
Trends in the bond dissociation energies for the binding of the alkali metal cations, Li+, Na+, K+, Rb+, and Cs+, to a series of ethers, 1-4 dimethyl ethers, 1 and 2 dimethoxy ethanes, and the crown ethers, 12c4, 15c5, and 18c6, are discussed. The bond energies have been determined in previous studies by analysis of the thresholds for collision-induced dissociation of the cation-ether complexes by xenon as measured in a guided ion beam tandem mass spectrometer. Details of the analysis of the data are reviewed and the accuracy of the results ascertained by comparison with theoretical results taken from the literature. Combined, the experimental and theoretical results provide an extensive thermochemical database for evaluation of the metal-crown complexes, a simple example of molecular recognition. These results indicate the importance of optimizing the metal-oxygen bond distances and the orientation of the local dipole on the oxygen towards the metal. Further, it is shown that excited state conformers of these complexes are probably observed in several systems as a result of interesting metal-dependent dynamics in the formation of the complexes. (C) 1999 Elsevier Science B.V.