Efficient coupling by oxygen accelerated photocatalyzed thiol-alkyne chemistry
作者:Michael L. Allegrezza、Adam M. Thompson、Alex J. Kloster、Dominik Konkolewicz
DOI:10.1016/j.polymer.2018.12.003
日期:2019.1
Thiolreactions have gained attention in many areas of chemical research, such as organic small molecule synthesis, polymer synthesis, and bimolecular coupling due to the “click” chemistry characteristics of this process. This work is a study of a novel method of photochemical thiol-alkyne reactions using alkyl halides and an Ir(ppy)3 photocatalyst. This process is shown to lead to rapid reactions
Hyperbranched Polymers with High Degrees of Branching and Low Dispersity Values: Pushing the Limits of Thiol–Yne Chemistry
作者:Alexander B. Cook、Raphael Barbey、James A. Burns、Sébastien Perrier
DOI:10.1021/acs.macromol.6b00132
日期:2016.2.23
We propose a versatile approach to the production of hyperbranchedpolymers with high degrees of branching and low dispersity values (Đ), involving slow monomer addition of a thiol/yne monomer to multifunctional core molecules in the presence of photoinitiator and under UV irradiation. The small thiol/yne monomer was synthesized via 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDC·HCl)
我们提出了一种生产支链度高,分散度值低的超支化聚合物的通用方法(Đ),包括在光引发剂的存在下和在紫外线照射下,将硫醇/炔单体缓慢地添加到多功能核心分子上。通过1-乙基-3-(3-(二甲基氨基)丙基)碳二亚胺盐酸盐(EDC·HCl)酯化反应合成小的硫醇/炔单体,并在不同浓度下进行间歇聚合。批量硫醇-炔聚合反应动力学快,分散度大,随浓度增加而增加。发现通过缓慢添加到多功能炔烃核(三(丙-2-炔-1-基)1,3,5-苯三羧酸酯)或烯烃核(三烯丙基1,3,5-苯三羧酸酯)中引入单体会降低分散性在单体浓度为0.5–2.0 M时。支化度由1确定在大多数情况下,1 H NMR光谱大于0.8。对于具有10mol%核心分子的0.5M单体浓度,发现增加核心分子的比例可将分散度降低至烯烃核和炔烃核的分散度分别低至1.26和1.38。还通过光散射尺寸排阻色谱法(SEC)检测来确定超支链结构的分子量,并通过SEC检
Hyperbranched Polymers by Thiol−Yne Chemistry: From Small Molecules to Functional Polymers
A new synthesis of hyperbranched polymers is outlined. This paper presents the synthesis of hyperbranched polymers by the recently highlighted thiol-yne reaction. In the thiol-yne reaction, a catalytic amount of photoinitiator and UV radiation are used to add two thiols across one alkyne bond at room temperature. This work demonstrates how the thiol-yne reaction can be used to form hyperbranched polymers from both small organic molecules and polymeric chains bearing an alkyne and a thiol. The UV-catalyzed reaction is fast, forming high-molecular-weight polymers after 20 min of UV irradiation.Hyperbranched polymers made by the thiol-yne reaction have the potential to serve as new materials for a variety of applications from catalytic support and drug delivery to viscosity modification.
Reversible single-chain selective point folding via cyclodextrin driven host–guest chemistry in water
作者:Johannes Willenbacher、Bernhard V. K. J. Schmidt、David Schulze-Suenninghausen、Ozcan Altintas、Burkhard Luy、Guillaume Delaittre、Christopher Barner-Kowollik
DOI:10.1039/c4cc03218g
日期:——
In the present communication we introduce a new platform technology for the reversible folding of single polymer chains in aqueous environment on the basis of cyclodextrin (CD) hostâguest chemistry and controlled radical polymerization protocols. The single-chain folding of adamantyl-β-CD α-Ï-functionalized poly(N,N-dimethylacrylamide) and its reversion at elevated temperatures were monitored by DLS and nuclear Overhauser enhancement spectroscopy (NOESY).