The Reactivity of Vinyl Nitrene Intermediates

有了这个奖项，有机和大分子化学项目支持辛辛那提大学的Gudmundsdottir教授，他的研究将集中在选择性形成、检测和调查乙烯基亚硝基中间体在溶液和固态中的反应性。乙烯基叠氮化物的直接辐照产生的氮化产物可归因于单线态乙烯基亚硝基，也可来自于乙烯基叠氮化物单线态激发态的协同重排。同样，直接光解2H-azirine衍生物形成单线态双自由基。为了避免乙烯基叠氮化物和2H-azirine前体的单线态反应性，制备了内置三重态增敏剂的乙烯基叠氮化物和2H-azirine衍生物。利用激光闪光光解和基质分离技术对这些叠氮化物和2h -氮嘧啶光解形成的三态乙烯基亚硝基中间体进行表征。得到了三联体乙烯基亚硝基乙烯在溶液中的反应性和动力学的详细图。初步结果表明，激光闪光光解具有内置三重态敏化剂的2H-azirine衍生物可以直接检测三重态乙烯基亚硝基中间体。这些结果开辟了一个新的领域，在亚硝基化学和中间体以前没有被表征，现在可以研究。这些乙烯基亚硝基前驱体的固态反应性将被研究，以了解它们的反应性如何受到周围晶格的影响。长期目标是使这些中间体稳定，以探索它们的物理性质。所提出的研究将导致在氩气基质和溶液中的三态乙烯基亚硝基乙烯的全面表征。由于这些中间体在溶液和固态中的化学反应途径在很大程度上是未知的，因此将对它们进行研究和鉴定。将进行分子模拟，以帮助表征这些化合物，并解释这些中间体的反应性。更好地了解三态亚硝基乙烯的反应性将有助于设计稳定的三态亚硝基乙烯。有了这个奖项，有机和大分子化学项目支持辛辛那提大学的Gudmundsdottir教授，他的研究将研究具有高自旋特性的三重态亚硝基中间体，因此是有机磁体的潜在候选者。对具有磁性的新型有机材料的探索源于它们为磁屏蔽、磁光开关和“智能”材料等应用提供新技术优势的潜力。本研究将培养研究生从事物理有机化学的基础研究。这些研究生将反过来训练本科生做研究，并让高中生接触科学研究。重点将放在吸引少数民族高中学生从事拟议的研究。

With this award, the Organic and Macromolecular Chemistry Program supports Professor Gudmundsdottir of the University of Cincinnati whose research will focus on selectively forming, detecting and investigating the reactivities of vinyl nitrene intermediates in solution and in the solid state. Direct irradiation of vinyl azides yields azirine products that can be attributed to formation of singlet vinyl nitrenes or can come from concerted rearrangement of the singlet excited state of the vinyl azides. Similarly, direct photolysis of 2H-azirine derivatives forms singlet biradicals. In order to bypass the singlet reactivity of the vinyl azide and 2H azirine precursors, vinyl azide and 2H-azirine derivatives with build-in triplet sensitizers have been prepared. The triplet vinyl nitrene intermediates that are expected to form by photolysis of these vinyl azides and 2H-azirines will be characterized using laser flash photolysis and matrix isolation. A detailed picture of the reactivities and kinetics of triplet vinyl nitrenes in solution will be obtained. Preliminary results imply that laser flash photolysis of 2H-azirine derivatives that have a built-in triplet sensitizer permit direct detection of triplet vinyl nitrene intermediates. These results have opened up a new field in nitrene chemistry and intermediates that have not previously been characterized can now be investigated. The solid state reactivity of these vinyl nitrene precursors will be studied in order to understand how their reactivity is affected by surrounding crystal lattices. The long term goal is to render these intermediates stable to explore their physical properties. The investigations that are proposed will lead to full characterization of triplet vinyl nitrenes in argon matrices and in solutions. Since the chemical reaction pathways for these intermediates in solution and in the solid state are largely unknown, they will be studied and identified. Molecular modeling will be performed to aid in the characterization of these compounds and to explain the reactivity of these intermediates. Better insight into the reactivity of triplet vinyl nitrenes will allow for the design of stable triplet nitrenes.With this award, the Organic and Macromolecular Chemistry Program supports Professor Gudmundsdottir of the University of Cincinnati whose research will study triplet nitrene intermediates that have high spin properties and are therefore potential candidates for organic magnets. The quest for new organic materials with magnetic properties arises from their potential to provide new technological advantages for applications such as magnetic shielding, magneto-optical switching, and 'smart' materials. The proposed research will train graduate students to do fundamental research in physical organic chemistry. These graduate students will in turn train undergraduate students to do research and expose high school students to scientific research. Emphasis will be placed on attracting minority high school students to work on the proposed research.