Convex Polycycles: Synthesis, Structure, and Chemistry of Heterotriquinanes

在化学系化学合成计划的支持下，加州大学戴维斯分校的马克·马斯卡尔教授正在研究定义了曲率的分子，特别是一类被称为“杂三喹烷”的碗状物质。这种曲率可以增加，直到分子变成球形，这样的系统也是研究的对象。具有感兴趣的性质的分子可以测试化学键理论的局限性，它们还为生产具有潜在科学、工程和商业用途的新性质的材料提供了独特的构建块。随着马斯卡尔教授和他的同事参与一系列K-12外展活动和促进本科生研究，特别是通过增加属于代表性不足群体的个人参与的计划，该资助项目的更广泛影响延伸到为社会带来的好处。该项目的同事将有机会在海外科学和文化研究项目中担任助教。受资助的研究围绕构象刚性的多喹烷杂环展开，范围从轻微弯曲的(杂三喹烷)到球形(非正十二面体)。这些多环环体系的化学被证明是罕见的和多方面的，使得能够合成具有典型化学键和结构理论极限的特殊物种，包括闻所未闻的高价模型(例如四价氧)、未知的两性离子物种(例如稳定的氧叶立德)和新颖的非平面芳环体系(例如杂五烯)。这些项目既将推进基础科学，又将为先进材料提供新的基石。根据该奖项开展的活动还将为属于代表性不足群体的本科生提供极好的机会，通过加州大学戴维斯分校为此类扩展专门设立的多个项目，以及开发纳入研究方面的新教育材料。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Chemical Synthesis Program in the Division of Chemistry, Professor Mark Mascal of the University of California-Davis is studying molecules that have defined curvature, in particular a class of substances called "heterotriquinanes" which are bowl-shaped. This curvature can be increased until the molecules become spherical and such systems are also a subject of investigations. Molecules with the properties of interest allow the limits of chemical bonding theory to be tested and they also provide unique building blocks for the production of materials with novel properties of potential utility to science, engineering, and commerce. The broader impacts of the funded project extend to the benefits accrued to society as Professor Mascal and his coworkers engage in a range of K-12 outreach activities and the promotion of undergraduate research, particularly via programs that increase the participation of individuals belonging to underrepresented groups. Coworkers on the project will have the opportunity to serve as teaching assistants on a scientific and cultural study abroad program.The funded research revolves around conformationally rigid polyquinane heterocycles that range from gently curved (heterotriquinanes) to spherical (heterododecahedranes). The chemistry of these polycyclic ring systems proves to be uncommon and multifaceted, enabling synthetic objectives that embody extraordinary species with properties at the limits of canonical chemical bonding and structural theory, including unheard-of models of hypervalency (e.g., tetravalent oxygen), unknown zwitterionic species (e.g., stable oxygen ylides), and novel, non-planar aromatic ring systems (e.g., heteroacepentalenes). These projects will both advance fundamental science and provide new building blocks for advanced materials. The activities carried out under this award will also provide excellent opportunities for the participation of undergraduate students belonging to underrepresented groups through multiple programs at UC-Davis specifically established for such outreach, as well as the development of new educational materials that incorporate aspects of the research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.