Gómez Borja, Francisco Vitor, Fernández-Nieto Fernando, Garcia-Rio Luis, Martín-Pastor M, Paleo M Rita, Sardina F Javier
Departamento de Química Física, Centro de Investigación en Química Biológica y Materiales Moleculares (CIQUS), Universidad de Santiago, 15782 Santiago (Spain), Fax: (+34) 981595012.
Chemistry. 2014 Sep 15;20(38):12123-32. doi: 10.1002/chem.201403194. Epub 2014 Aug 8.
The complexation of an anionic guest by a cationic water-soluble pillararene is reported. Isothermal titration calorimetry (ITC), (1)H NMR, (1)H and (19)F DOSY, and STD NMR experiments were performed to characterize the complex formed under aqueous neutral conditions. The results of ITC and (1)H NMR analyses showed the inclusion of the guest inside the cavity of the pillar[5]arene, with the binding constant and thermodynamic parameters influenced by the counter ion of the macrocycle. NMR diffusion experiments showed that although a fraction of the counter ions are expelled from the host cavity by exchange with the guest, a complex with both counter ions and the guest inside the pillararene is formed. The results also showed that at higher concentrations of guest in solution, in addition to the inclusion of one guest molecule in the cavity, the pillararene can also form an external complex with a second guest molecule.
报道了阳离子水溶性柱芳烃与阴离子客体的络合作用。进行了等温滴定量热法（ITC）、¹H NMR、¹H和¹⁹F DOSY以及STD NMR实验，以表征在中性水溶液条件下形成的络合物。ITC和¹H NMR分析结果表明客体被包合在柱[5]芳烃的空腔内，结合常数和热力学参数受大环抗衡离子的影响。NMR扩散实验表明，虽然一部分抗衡离子通过与客体交换而从主体空腔中排出，但在柱芳烃内部形成了同时含有抗衡离子和客体的络合物。结果还表明，在溶液中客体浓度较高时，除了一个客体分子被包合在空腔内，柱芳烃还能与第二个客体分子形成外部络合物。
