The influence of calix[4]arene upper rim substitution on the complexation with Li+, Na+, K+ was studied by 1H NMR spectroscopy. Calix[4]arenes 1-4 namely 25,26,27,28-tetrakis(3-oxapentyloxy)calix[4]arene (1), its 5,17-diamino (2) and 5,17-dinitro derivative (3) as well as 25,26,27,28-tetrakis(3,6,9-trioxadecyloxy)calix[4]arene (4) having four monoalkyloligoethylene glycol chains on the lower rim have been studied. No complexation has been observed for Li+. Two electron-donating NH2 groups on the calixarene upper rim (compound 2) improve the complexation ability for Na+ and K+ compared with parent calixarene 1. The electron-withdrawing nitro groups in 3 have the opposite influence. It seems that the complexation of alkali metal ions studied is not significantly influenced by the increasing number of donor atoms (from eight in 1 to sixteen in 4) available for complexation on the lower rim. The position of sodium cation in 1 . Na+ and 4. Na+ is supposed to be in close proximity of phenolic oxygens based on 1H and 13C NMR data. The error analysis is given for the stability constant determination from NMR data.
使用1H NMR光谱研究了Calix [4]
芳烃上缘取代对其与Li +,Na +,K +络合作用的影响。研究了四个单烷基寡
乙二醇链被连接到下缘的Calix [4]
芳烃1-4,即25,26,27,28-四(3-氧代戊氧基)Calix [4]
芳烃(1),其5,17-二
氨基(2)和5,17-二硝基衍
生物(3)以及25,26,27,28-四(3,6,9-三氧代癸氧基)Calix [4]
芳烃(4)。没有观察到Li +的络合。Calix
芳烃上缘的两个电子给予的NH2基团(化合物2)与父Calix
芳烃1相比,提高了Na +和K +的络合能力。电子吸引的硝基团在3中具有相反的影响。研究的碱
金属离子的络合似乎不受可用于下缘络合的给体原子数量(从1中的8到4中的16)的增加的显著影响。根据1H和13C NMR数据,Na +在1.Na +和4.Na +的位置应该靠近
酚氧基。给出了从NMR数据确定稳定常数的误差分析。