摘要：
将前体N,N'(3-胺基苯基)-2,6-二甲酰胺吡啶(1)和5,5-二甲基-1,9-二甲酰基二吡咯甲烷(2)进行缩合作用得到[1+1] Schiff碱大环3.进一步将Schiff碱大环3还原得到饱和大环4.采用1H NMR,FT-IR,FABMS和元素分析等对大环的组成进行了表征,通过X射线单晶衍射技术解析了大环4的晶体结构.采用紫外-可见吸收光谱、核磁和等温量热滴定等技术对大环3和4分别与AcO-阴离子的键合作用进行了考察,获得了反应的键合比、键合常数(K)及△rHm,△rSm,△rGm等热力学参数信息.结果表明,大环3与AcO氢键作用的键合比为1∶1,键合常数K≈105 L·tmol-1,具有更柔性的环状骨架大环4与AcO-作用的键合比为1∶2,Ka1≈ 103 L·mol-1,Ka2≈105 L·mol-1.%[1+ 1] Schiff base macrocycle 3 has been synthesized from the reaction of precursors N,N'-bis(3-aminophenyl)-pyridine-2,6-dicarboxamide (1) with 5,5-dimethyl-l,9-diformyldipyrromethane (2),and furthermore the macrocycle 3 was reduced to the corresponding saturated macrocycle 4.The two macrocycles were characterized by 1H NMR,FT-IR,FABMS spectroscopies and elemental analysis,and the crystal structure of 4 was determined by X-ray diffraction analysis.Properties of the two macrocycles hydrogen-bonding interactions with AcO-were investigated using UV-Vis,1n NMR,the isothermal titration calorimeter (ITC),as well as density functional theory (DFT) calculations.The stoichiometric ratio,binding constant (K) and the thermodynamic parameters (△rHm,△rSm and △rGm) of binding interactions were obtained.The results demonstrate that the macrocycle 3 binds AcO-with a 1 ∶ 1 binding stoichiometry (Ka≈ 105 L·mol-1),and the more flexible macrocyclic receptor 4 binds AcO-with a 1 ∶ 2 binding stoichiometry (Ka1 ≈ 103 L·mol-1,Ka2 ≈ 105 L·mol-1).
