Studies on Oxygenation and Catalytic Oxidation of Cobalt (II) Polyether-Bridged Dihydroxamates

Li Hongbo1, 2 , Wei Xingyao1, Zhang Chunchun1,   Du Yin1, Qin Shengying1*
(1 Department of Chemistry, Sichuan University Chengdu 610064)
(2 Department of Biotechnological and Chemical Engineering, Wuhan Polytechnic University, Wuhan 430023)

Abstract Three new p-, m- and o-isomers of polyether-bridged dihydroxamic acids were prepared in multi-step reaction from 1,8-dichloro-3,6-dioxaoctane and p-, m- or o-hydroxy-benzoic acid. The differences of the ligands in IR, 1H NMR and their complexation performance on cobalt ion were well explained by the energy-minimized models in Chem3D (MM2). Saturated oxygen uptaken by the cobalt (II) complexes were measured in pyridine solvent at different temperatures, and the equilibrium constants Ko2 and thermodynamic parameters DH°, DS° for oxygenation were calculated. Meanwhile the complexes are applied in the catalytic oxidation of p-xylene successfully. The influences of the bonding position of the polyether-bridge on dioxygen-affinities and catalytic performance of the complexes are also discussed.
Key words Open-chain crown ether, Dihydroxamic acid, Cobalt (Ⅱ) complex, Synthesis, Oxygenation, Catalytic oxidation

　

聚醚桥连二异羟肟酸钴(Ⅱ)配合物的氧合与催化氧化性能研究

李鸿波1,2 魏星耀1 张春春1 杜瑛1 秦圣英1*
(1四川大学化学学院 成都 610064 2武汉工业学院生物与化学工程系 武汉 430023)

摘要 由对羟基苯甲酸及其邻、间位异构体与1,8-二氯代-3,6-二氧杂辛烷出发，经多步反应制备了聚醚桥连的二异羟肟酸对、间和邻位异构体。借助Chem3D(MM2)模拟了配体分子的最低能量构象图，解释了它们在IR谱、1H NMR谱和配位性能等之间的差异。在吡啶溶液中和不同温度下，测定了钴(Ⅱ)配合物的饱和吸氧量，求出了它们的氧加合常数KO2和热力学参数DH°, DS°，并将其应用于对二甲苯的催化氧化反应中，考察了聚醚桥链的键连部位对配合物的氧合与催化性能的影响。
关键词 开链冠醚 二异羟肟酸 钴(Ⅱ)配合物 合成 氧合反应 催化氧化

李鸿波 男，29岁，博士，从事仿生载氧和催化氧化等领域的研究。*联系人 E-mail:qin-shengying@163.com
国家自然科学基金资助项目(20072025)
2002-07-01收稿，2002-11-28修回

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