Department of Chemistry, Indiana University Northwest, Gary, Indiana 46408, USA.
Dalton Trans. 2020 Mar 21;49(11):3545-3552. doi: 10.1039/c9dt04869c. Epub 2020 Mar 2.
The synthesis of a heteromacrocyclic bifunctional chelator with phosphonic acid pendent arms is presented along copper(ii) complexation. Ligand NS-POH featuring N,N'-bis-substituted phosphonate pendent arms was isolated in respectable yields, characterized, and chelated to copper(ii). Implementation of both Moedritzer-Irani and Kabachnik-Fields conditions using aza-thia macrocycle 1,8-dithia-4,11-diazacyclotetradecane afforded 1,8-dithia-4,11-diazacyclotetradecane-4,11-diyl-bis-(methylene)-bis-(phosphonic acid) (NS-POH). Kinetic NMR studies provided four acid dissociation constants with respect to hydronium ion concentration. Benesi-Hildebrand binding experiment provided a conditional formation constant of 2.8 × 10 M. Heteromacrocycle NS-POH readily formed an encapsulated copper(ii) chelate at room temperature, which was examined through EPR analysis.
本文报道了一种具有膦酸侧臂的杂大环双功能螯合剂的合成及其与铜（ii）的络合。具有 N，N'-双取代膦酸侧臂的配体 NS-POH 以可观的产率分离出来，经过表征后与铜（ii）螯合。使用氮杂硫代大环 1,8-二硫代-4,11-二氮杂环十四烷，通过 Moedritzer-Irani 和 Kabachnik-Fields 条件实现了 1,8-二硫代-4,11-二氮杂环十四烷-4,11-二基-双（亚甲基）-双（膦酸）（NS-POH）的合成。动力学 NMR 研究提供了四个关于氢离子浓度的酸离解常数。Benesi-Hildebrand 结合实验提供了 2.8×10 M 的条件形成常数。杂大环 NS-POH 可在室温下轻易形成包裹的铜（ii）螯合物，通过 EPR 分析进行了检测。
