Synthesis and complexation properties of ditopic ligands built from a macrocyclic and an open chain chelator moiety
作者:Liselotte Siegfried、Marcus Honecker、Andreas Schlageter、Thomas A. Kaden
DOI:10.1039/b308966p
日期:——
Two heteroditopic ligands 5 and 6, containing the macrocyclic unit cyclam and the open chain ligand 2,2′,2″-triaminotriethylamine (tren), as well as the pendant macrocycle 1-(2-methylaminoethyl)-1,4,8,11-tetraazacyclotetradecane 9, were synthesized. Their complexation potential towards Cu2+ and Ni2+ was studied using potentiometric pH-measurement and spectrophotometric titrations, from which the stability
两个异位 配体 5和6,包含大环单元仙客来 和开放链 配体 2,2',2”-三氨基三乙胺(tren)以及侧链 大循环 1-(2-甲基氨基乙基)-1,4,8,11-四氮杂环十四烷 合成了图9。用电位pH值测定和分光光度滴定法研究了它们对Cu 2+和Ni 2+的络合潜力,由此确定了该化合物的稳定性常数和存在范围。两个都配体 5和6形成一系列单核MLH n (n = 3,2,1,0 )和双核M 2 LH p (p = 0,-1,-2)物种,在某些情况下还形成二聚体复合物(ML)2 H m (m = 2、1、0)。为了比较目的,使用9观察到的物种的结构配体 可以从它们的光谱特性推论出图5和图6。因此,在配合物MLH n中,金属离子总是与大环结合,而在M 2 LH p物种中,一种金属与大循环而另一方则由特伦部队负责。动力学测量表明,金属离子首先结合到更具反应性的开链单元上,但随后转移到金属离子上。仙