Zhang Dawei, Chatelet Bastien, Serrano Eloisa, Perraud Olivier, Dutasta Jean-Pierre, Robert Vincent, Martinez Alexandre
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062 (P. R. China).
Laboratoire de Chimie, École Normale Supérieure de Lyon, CNRS, UCBL, 46, Allée d'Italie, 69364 Lyon (France).
Chemphyschem. 2015 Oct 5;16(14):2931-5. doi: 10.1002/cphc.201500610. Epub 2015 Aug 25.
The recognition properties of heteroditopic hemicryptophane hosts towards anions, cations, and neutral pairs, combining both cation-π and anion-π interaction sites, were investigated to probe the complexity of interfering weak intermolecular interactions. It is suggested from NMR experiments, and supported by CASSCF/CASPT2 calculations, that the binding constants of anions can be modulated by a factor of up to 100 by varying the fluorination sites on the electron-poor aromatic rings. Interestingly, this subtle chemical modification can also reverse the sign of cooperativity in ion-pair recognition. Wavefunction calculations highlight how short- and long-range interactions interfere in this recognition process, suggesting that a disruption of anion-π interactions can occur in the presence of a co-bound cation. Such molecules can be viewed as prototypes for examining complex processes controlled by the competition of weak interactions.
研究了具有双位点识别特性的半环番主体对阴离子、阳离子和中性对的识别性能，该主体结合了阳离子-π和阴离子-π相互作用位点，以探究干扰性弱分子间相互作用的复杂性。核磁共振实验表明，并得到CASSCF/CASPT2计算的支持，通过改变缺电子芳环上的氟化位点，阴离子的结合常数可被调节高达100倍。有趣的是，这种微妙的化学修饰还可以逆转离子对识别中协同作用的符号。波函数计算突出了短程和长程相互作用在这一识别过程中的干扰方式，表明在共结合阳离子存在的情况下，阴离子-π相互作用可能会受到破坏。这类分子可被视为用于研究由弱相互作用竞争控制的复杂过程的原型。
