Captodative Radicals, Diradicals, and Their Peroxides

有机动力学项目的这个续展奖项是为了支持科罗拉多大学博尔德分校的Tad Koch博士的研究。这项研究将集中在通过给电子和吸电子基团的共同作用而稳定的卡位自由基。氨基和羧基的影响最大。这项研究将进一步探索取代基在刚性环上的2-氧吗啉自由基，从而使电子相互作用最大化。这些自由基与它们的二聚体在溶液中处于平衡状态，在包括水在内的各种溶剂中作为温和的单电子还原剂发挥作用。根据烷基的位置，自由基按化学计量将分子氧还原为过氧化氢或形成可分离的过氧化氢。这项研究的长期目标是设计、制备和使用碳酸基。具体目标是设计、合成和表征新的2-氧吗啉自由基和双自由基，它们可以可逆地与氧结合，形成有用的过氧化物，或者作为大分子结构的交联剂。由此产生的过氧物的热和光化学反应活性将被确定。2-氧吗啉自由基的氧化还原活性和成键稳定性将被确定为结构和介质的函数。将设计和合成具有增强氧化还原活性的新结构。

This renewal award in the Organic Dynamics Program is in support of the research of Dr. Tad Koch at the University of Colorado at Boulder. The research will focus on captodative radicals which are stabilized through the combined effect of electron-donating and electron-withdrawing groups. This effect should be maximum with amino and carboxy substituents. The research will explore further the 2-oxomorpholinyl free radical whose substituents are in a rigid ring which maximizes the electronic interaction. These free radicals exist in equilibrium with their dimers in solution and function as mild one-electron reducing agents in a wide variety of solvents including water. Depending upon the placement of alkyl groups, the radicals reduce stoichiometrically molecular oxygen to hydrogen peroxide or form isolable peroxides. The long range goal of the research is the design, preparation and use of captodative radicals. The specific objectives are the design, synthesis and characterization of new 2-oxomorpholinyl radicals and diradicals which will either bind oxygen reversibly, form useful peroxides or serve as crosslinking agents for macromolecular structures. The thermal and photochemical reactivity of the resulting peroxides will be established. The redox activity and captodative stabilization of 2-oxomorpholinyl radicals as a function of structure and medium will be determined. New structures with enhanced redox activity will be designed and synthesized.