Theoretical Design of a New Allosteric Switch and Fluorescence Chemosensor Double Functional Devices of Aza-Crown Ether

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• 作者：Weiwei Li ; Xinliang Yu ; Xueye Wang
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：January 26, 2017
• 年：2017
• 卷：121
• 期：3
• 页码：1436-1441
• 全文大小：359K
• ISSN：1932-7455

文摘

A novel molecular device (trans-azobenzene embedded N-(11-pyrenyl methyl)aza-21-crown-7) with double functional devices was designed on the basis of theoretical calculations. Pyrenyl methyl covalently bonded to aza-21-crown-7 at the nitrogen position interacting with a series of alkaline-earth metal cations (Mg²⁺, Ca²⁺, Sr²⁺, and Ba²⁺) was investigated. The fully optimized geometries and real frequency calculations were investigated using a computational strategy based on density functional theory at B3LYP/6-31G(d) level. Free ligand (L) and their metal cation complexes (L/M²⁺) were studied using mixed basis set (6-31G(d) for the atoms C, H, O, and N and LANL2DZ for alkaline-earth metal cations Mg²⁺, Ca²⁺, Sr²⁺, and Ba²⁺. The natural bond orbital analysis that is based on optimized geometric structures was used to explore the interaction of L/M²⁺ molecules. The absorption spectra of L and L/M²⁺, excitation energies, and absorption wavelength for their excited states were studied by time-dependent density functional theory with 6-31G(d) and LANL2DZ. A new type of molecular device is found, which has the selectivity to Ca²⁺ and the emission fluorescence of L/Ca²⁺ under the condition of illumination. This molecular device would serve as an allosteric switch and a fluorescence chemosensor.