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

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。 均聚是阳离子聚合，当然共聚是自由基聚合。 这个项目将扩展这种化学，以证明阴离子聚合也可以带来的“电荷转移”反应的供体和受体烯烃和它们产生的环丁烷。 作为第二个主题的知识和能力，关于“电荷转移”的相互作用将被用来控制自由基加成聚合。 在交替共聚反应中涉及"电荷转移"络合物的问题已经讨论了很长时间，但没有定论。 本计画将探讨加入非聚合性给体或受体分子对交替共聚反应的影响，这些分子将竞争性地络合其中一种共聚单体。 通过这样的相互作用，自由基的稳态浓度将升高或降低，导致以目前无法获得的方式控制所得共聚物的序列分布和组成。开展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所有方面，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，隔离和彻底的特点，使研究人员在合成聚合物化学有用的知识。

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.