文献类型：期刊文献

中文题名：多齿氨基酚氧基锌络合物催化外消旋β-丁内酯开环聚合研究

英文题名：Ring-Opening Polymerization of rac-β-Butyrolactone Catalyzed by Zinc Complexes Bearing Multidentate Aminophenolate Ligands

作者：王真[1];马海燕[1]

机构：[1]华东理工大学化学与分子工程学院,金属有机化学研究室,上海200237

年份：2025

卷号：51

期号：3

起止页码：295

中文期刊名：华东理工大学学报(自然科学版)

外文期刊名：Journal of East China University of Science and Technology

收录：;北大核心:【北大核心2023】；

基金：国家自然科学基金(21871082)。

语种：中文

中文关键词：苯并咪唑取代氨基酚类配体;锌络合物;外消旋β-丁内酯;开环聚合;间规选择性

外文关键词：benzoimidazolyl substituted aminophenol ligand;zinc complex;rac-β-butyrolactone;ring-opening polymerization;syndioselective

摘要：聚-3-羟基丁酸酯(P3HB)的立体规整性对其力学性能有很大影响,设计合成高效催化剂实现外消旋β-丁内酯立体选择性开环聚合成为该领域的难点和热点问题。本文合成了一系列具悬垂苯并咪唑结构的氨基酚氧基锌络合物Zn1~Zn7,并对Zn4的分子结构进行X-ray单晶衍射表征。在异丙醇存在下,该系列锌络合物对外消旋β-丁内酯开环聚合具有较好的催化活性,周转频率(TOF)最高达116 h^(-1),并具有一定的间规立体选择性,其间规度(P_(r))范围为0.58~0.66。配体的各取代基,尤其是酚氧基邻位取代基,对络合物催化活性影响显著,但对立体选择性的影响不明显。基于活性中心结构、聚合物端基的分析结果,推测该系列络合物通过配位-插入机理催化外消旋β-丁内酯,聚合得到异丙氧基和羟基封端的线性P3HB。此外,在不影响立体规整度判断的情况下,开发了一种利用核磁氢谱评价P3HB规整度的方式,该方式较传统定量碳谱的表征方式更加便捷、经济。
The stereotacticity of poly(3-hydroxybutyrate)(P3HB)has a great impact on its physical and mechanical properties,thus the design and synthesis of high-performance catalysts capable of catalyzing the stereoselective ring-opening polymerization of racemicβ-butyrolactone(rac-β-BL)are challenging and becoming a hot issue.In this work,a series of aminophenolate zinc complexes with pendant benzoimidazolyl groups Zn1—Zn7 were synthesized via the reaction of the corresponding proligands L1H—L7H with the same amount of Zn[N(SiMe3)2]2,respectively.Among them,the proligands L4H,L7H and zinc complexes Zn4,Zn7 were newly reported,which were further characterized by elemental analysis and NMR spectroscopy.The molecular structure of complex Zn4 was further determined by X-ray diffractional analysis,where the metal center is four-coordinated by the tridentate aminophenolate ligand and one silylamido group.Complexes Zn1—Zn7 could catalyze the ring-opening polymerization of rac-β-BL with moderate activities,producing P3HBs with syndiotacticities up to P_(r)=0.66.The substituents on the ligand frameworks showed noticeable influences on the activities of these complexes,with the influence of ortho-substituent of the phenolate ring most remarkable.Complex Zn1 with an ortho-tert-butyl group of less steric bulkiness meanwhile electron-donating exhibited the highest activity,TOF=116 h^(-1);the introduction of electron-withdrawing chlorine brought unfavorable effect on the polymerization of rac-β-BL,leading to complex Zn4 exhibiting a decreased activity.The molecular weights of resultant P3HBs are in good consistency with the theoretical values,and the molecular weight distributions are generally narrow(M_(w)/M_(n)≈1.15—1.38).On the basis of 1H-NMR tracking reactions and the result of 1H-NMR spectrum of typical oligomer,it is proposed that the polymerization of rac-β-BL is initiated by the in-situ formed unique zinc isopropoxide species and the P3HB chain is propagated via coordination-insertion process to give linear polymers end-capped with one isopropoxyl group and one hydroxy group.Moreover,an easy way of evaluating the stereoregularity of P3HB using inexpensive and convenient 1H-NMR spectrometry was developed.