Bifunctional Free Radical Initiators and Azoxyalkane Cyclizations

本研究的重点有三个方面。 首先，偶氮和佩雷斯特 含有双官能和三官能自由基引发剂的聚合物将 合成并作为星星聚合物和嵌段聚合物的前体进行检查 在嵌段界面含有官能团的共聚物。 第二、 含有氧化偶氮基团的分子的自由基化学将是 审查的具体重点是确定，根据 偶氮氧的位置，分子内环化机理， 乙烯释放 最后，卤素形成的机制 与偶氮烷烃和1，2-二烷基肼的配合物将被阐明 并检查所得加合物的自由基化学。 研究生 和博士后学生将被介绍到自由基 上述有机分子和自由基的化学 聚合法 有了这个奖项，有机和高分子化学计划 支持保罗·恩格尔博士的研究和教育活动， 莱斯大学化学系。 恩格尔博士将集中精力 有机分子的合成与表征研究 含有两个或多个偶氮或过酸酯基团。 激活这些群体 与热或光一起导致高反应性位点， 自由基 通过将偶氮或过酸酯基团定位在 分子，从而定义自由基被 恩格尔博士将研究两个网站内的机制， 相同的分子偶联形成环状分子， 一个分子上的哪些位点与另一个分子反应以传播 自由基的形成，以及随后的聚合物的生长， 分子的形状和组成。 恩格尔的教育活动 参与培训研究生和博士后学生的综合， 含有偶氮和过酸酯基团的分子，它们的活化形成 自由基，以及随后的化学特性， 这些反应中间体。

The focus of this research is three fold. First, azo and perester containing bi- and tri-functional free-radical initiators will be synthesized and examined as precursors to star polymers, and block copolymers containing functional groups at the block interfaces. Second, the radical chemistry of molecules containing an azoxy group will be examined with a specific emphasis on determining, depending on the position of azoxy group, the mechanisms of intramolecular cyclization and ethylene evolution. Lastly, the mechanism by which halogens form complexes with azoalkanes and 1,2-dialkylhydrazines will be elucidated and the radical chemistry of the resulting adduct examined. Graduate and postdoctoral students will be introduced to the free radical chemistry of the aforementioned organic molecules, and free radical polymerization. With this award, the Organic and Macromolecular Chemistry Program supports the research and educational activities of Dr. Paul Engel of the Department of Chemistry at Rice University. Dr. Engel will focus his research on the synthesis and characterization of organic molecules containing two or more azo or perester groups. Activating these groups with either heat or light leads to highly reactive sites referred to as free radicals. By positioning the azo or perester groups within the molecule, and thereby defining the sites at which the free radicals are generated, Dr. Engel will examine the mechanism by which two sites within the same molecule couple to form a cyclic molecule, and the mechanisms by which sites on one molecule react with another molecule to propagate the formation of the radical, and the subsequent growth of polymers with new molecular shapes and composition. Dr. Engel's educational activities involve training graduate and postdoctoral students in the synthesis of molecules containing azo and perester groups, their activation to form free radicals, and the characterization of the subsequent chemistry of these reactive intermediates.