关键词: 间苯二甲酰胺, 酚环, Schiff碱大环, 阴离子, 识别

A[1+1] Schiff base macrocyclic compound L containing isophthalamide unit and phenol rings has been synthesized from the reaction of precursors N,N'-(6-amino-2-pyridyl)-1,3-dicarboximide with 5,5'-methylene bis-salicylaldehyde by Schiff-base condensation. The macrocycle L was characterized via ¹H NMR, FABMS, and elemental analysis. The crystal structure of L was determined by X-ray diffraction analysis, and it has a folded clamp conformation. In the crystal state of L, individual macrocycles were assembled into columnar structures with 1D channel through intermolecular hydrogen bonding and π-π stacking interactions. The results show that the macrocycle L displays a selective recognition ability for H₂PO₄^- and HP₂O₇^3- anion respectively by the coordination reaction of L with a series of anions using UV-Vis absorption spectra technique. Furthermore, the coordination reaction of L with H₂PO₄^- or HP₂O₇^3- anion was investigated via UV-Vis spectra, ¹H NMR and the isothermal titration calorimeter (ITC) respectively. The stoichiometric ratio, the association constant (K) and the thermodynamic parameters (△_rH_m, △_rS_m and △_rG_m) of the coordination reaction were obtained. The results show that the macrocycle L binds H₂PO₄^- with a 1:1 binding stoichiometry, and binds HP₂O₇^3- to form the structure of sandwich-type with a bonding ratio of 2:1.

Key words: isophthalamide, phenol ring, Schiff-base macrocycle, anion, recognition