Polar Tetramethylene Biradicals in "Charge Transfer" Cycloaddition and Polymerization Reactions

“电荷转移”环加成和聚合反应中的极性四亚甲基双自由基

• 批准号: 9817239
• 负责人: Henry Hall
• 金额: $ 27万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-02-01 至 2002-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9817239&HistoricalAwards=false
• 关键词: Polar; Tetramethylene; Biradicals; Charge; Transfer

9817239HallIn earlier studies it has been shown that "charge transfer" reactions can be used to initiate vinyl homo- and copolymerizations. The homopolymerizations were cationic and, of course, the copolymerizations were free radical. This project will extend this chemistry to demonstrate that anionic polymerizations can also be brought about by "charge transfer" reactions of donor and acceptor olefins and their resulting cyclobutanes. As a second topic knowledge and capabilities regarding "charge transfer" interactions will be used to control free radical addition polymerizations. The involvement of "charge transfer" complexes in alternating copolymerizations has been long and rather inconclusively discussed. This project will investigate the effect on alternating copolymerizations of added non-polymerizable donor or acceptor molecules which will competitively complex one of the comonomers. By such interactions, the steady state concentrations of free radical will be raised or lowered leading to control of the sequence distribution and composition of the resulting copolymers in ways not accessible today.%%%Valuable educational experience will be gained by the graduate students and postdoctoral associates carrying out this program. They will experience all the aspects of organic synthesis including the latest reaction techniques and reagents. Deliberate polymerizations will be carried out with free radical, and ionic initiators to demonstrate that these are satisfactory monomers. The polymeric products will be separated, isolated and thoroughly characterized, giving the researchers useful knowledge in synthetic polymer chemistry.

9817239Hall 在早期的研究中已经表明，“电荷转移”反应可用于引发乙烯基均聚和共聚。 均聚是阳离子的，当然，共聚是自由基的。 该项目将扩展这一化学过程，以证明阴离子聚合也可以通过供体和受体烯烃及其生成的环丁烷的“电荷转移”反应来实现。 作为第二个主题，有关“电荷转移”相互作用的知识和能力将用于控制自由基加成聚合。 交替共聚中“电荷转移”配合物的参与已经被长期讨论且相当不确定。 该项目将研究添加的不可聚合供体或受体分子对交替共聚的影响，这些分子将竞争性地络合一种共聚单体。 通过这种相互作用，自由基的稳态浓度将升高或降低，从而以目前无法达到的方式控制所得共聚物的序列分布和组成。%%%执行该项目的研究生和博士后将获得宝贵的教育经验。 他们将体验有机合成的各个方面，包括最新的反应技术和试剂。 将使用自由基和离子引发剂进行有意的聚合，以证明这些是令人满意的单体。 聚合物产品将被分离、分离和彻底表征，为研究人员提供合成聚合物化学方面的有用知识。