| Institution: | 1. Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 P. R. China
University of Chinese Academy of Sciences, Beijing, 100190 P. R. China;2. Physical Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K8-88, Richland, Washington, 99352 USA;3. Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 P. R. China |
| Abstract: | Manipulation of the emerging anion–π interactions in a highly cooperative manner through sophisticated host design represents a very challenging task. In this work, unprecedented tetrahedral anion–π receptors have been successfully constructed for complementary accommodation of tetrahedral and relevant anions. The synthesis was achieved by a macrocycle-directed approach by using large macrocycle precursors bearing four reactive sites, which enabled a kinetic-favored pathway and afforded the otherwise inaccessible tetrahedral cages in considerable yields. Crystal structure suggested that the tetrahedral cages have an enclosed three-dimensional cavity surrounded by four electron-deficient triazine faces in a tetrahedral array. The complementary accommodation of a series of tetrahedral and relevant anions including BF4−, ClO4−, H2PO4−, HSO4−, SO42− and PF6− was revealed by ESI-MS and DFT calculations. Crystal structures of ClO4− and PF6− complexes showed that the anion was nicely encapsulated within the tetrahedral cavity with up to quadruple cooperative anion–π interactions by an excellent shape and size match. The strong anion–π binding was further confirmed by negative ion photoelectron spectroscopy measurements. |
