1H NMR investigation of solvent effects in aromatic stacking interactions
1H NMR investigation of solvent effects in aromatic stacking interactions
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DOI：
10.1021/ja015817m
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发表时间：
2001-08-08
影响因子：
15
通讯作者：
Iverson, BL
中科院分区：
文献类型：
--
作者：
Cubberley, MS;Iverson, BL
现代有机化学面临的最大挑战之一是设计和合成非生物化合物，以模仿生物大分子的精致复杂结构和/或功能。利用氢键、扭转限制和疏溶剂相互作用，获得了具有良好定义的致密构象的低聚物。(1)在本实验室中，芳香电子供体-受体相互作用被用于设计在水溶液中采用新颖的褶状二级结构的aedamerer -foldamers。本文报道了在溶剂和溶剂混合物中对毛囊体单体进行的详细的H-1 NMR结合研究，这些研究涵盖了广泛的极性范围。使用包含高阶配合物和自相关配合物形成的模型对结合数据进行曲线拟合分析，得出络合的自由能与经验溶剂极性参数E-T之间的线性自由能关系（30）。从这些研究中，富电子和缺电子的聚体单体的结合被认为主要是由极性溶剂中的疏水相互作用驱动的。然而。这些相互作用的大小在很大程度上由供体-受体络合物的几何形状调制，而这反过来又由单体的缺电子和富电子芳香面之间的静电互补性决定。
One of the marquis challenges in modem Organic Chemistry concerns the design and synthesis of abiotic compounds that emulate the exquisite complex structures and/or functions of biological macromolecules. Oligomers possessing the propensity to adopt well-defined compact conformations, or foldamers, have been attained utilizing hydrogen bonding, torsional restriction, and solvophobic interactions.(1) In this laboratory, aromatic electron donor-acceptor interactions have been exploited in the design of aedamers-foldamers that adopt a novel, pleated secondary structure in aqueous solution. Herein is reported detailed H-1 NMR binding studies of aedamer monomers that were carried out in solvents and solvent mixtures covering a broad polarity range. Curve-fitting analysis of the binding data using a model that incorporated the formation of higher order and self-associated complexes yielded a linear free energy relationship between the free energy of complexation and the empirical solvent polarity parameter, E-T(30). From these studies, the association of electron-rich and electron-deficient aedamer monomers was seen to be driven primarily by hydrophobic interactions in polar solvents. However. the magnitude of these interactions is modulated to a significant extent by the geometry of the donor-acceptor complex, which, in turn, is dictated by the electrostatic complementarity between the electron-deficient and electron-rich aromatic faces of the monomers.