Key Laboratory for Advanced Material and Department of Chemistry, East China University of Science and Technology, Shanghai 200237, People's Republic of China.
J Mol Model. 2012 Jul;18(7):3311-20. doi: 10.1007/s00894-011-1350-7. Epub 2012 Jan 18.
The structures and properties of noncovalent interactions involving three imidazoliophane receptors 1-3 and halide anions have been investigated by means of density functional theory calculations. To account for the influence of the solvent environment, the implicit polarized continuum model was also employed. For the halogenated cyclophane receptors 1 and 2, the halide ions are held by a bidentate array of halogen bonds (C-Br/C-I...X(-)), while multiple hydrogen-bonding interactions (C-H...X(-)) are present in the complexes of the nonhalogenated macrocyclic receptor 3. To accommodate the negatively charged guest anions, the structures of 1 and 2 fully reorganize into a calix-like shape, while both the imidazole and benzene rings in 3 tend to point towards the anions and thus rotate to form a cage-like shape. In both the gas phase and aqueous solution, the binding affinities of the anions for halogen-bonding receptors 1 and 2 become stronger than those for hydrogen-bonding receptor 3. The results reported here should prove to be of great value in the design and synthesis of effective and selective anion receptors based on halogen bonding.
三种咪唑并菲咯烷受体 1-3 与卤化物阴离子之间的非共价相互作用的结构和性质已通过密度泛函理论计算进行了研究。为了考虑溶剂环境的影响，还采用了隐式极化连续模型。对于卤代环戊烷受体 1 和 2，卤化物离子通过卤素键（C-Br/C-I...X(-)）的双齿阵列固定，而在非卤代大环受体 3 的配合物中存在多个氢键相互作用（C-H...X(-)）。为了容纳带负电荷的客体阴离子，1 和 2 的结构完全重组为杯状形状，而 3 中的咪唑环和苯环都倾向于指向阴离子，从而旋转形成笼状形状。在气相和水溶液中，阴离子与卤素键受体 1 和 2 的结合亲和力均强于与氢键受体 3 的结合亲和力。这里报道的结果对于基于卤素键的有效和选择性阴离子受体的设计和合成应该具有重要价值。
