Monocoordinated carbon, boron and phosphorus species

碳是构成生命元素（DNA、RNA等）的建筑材料。碳通常形成四个化学键。在这个由化学部化学合成项目资助的项目中，加州大学圣地亚哥分校（UCSD）化学与生物化学系的Guy Bertrand教授试图制备违反四键规则的化合物。人们认为这些新的碳物种本身就不稳定，这阻碍了它们的分离。伯特兰教授的实验室最近开发了一种新方法来制备一种叫做碳烯的化合物，这种化合物与碳只有两个键。这些方法扩展到碳化合物，碳中只有一个键。这些物种的可用性可以更好地理解碳的化学反应是如何发生的，从而可以控制含碳物种的反应性。最终，这项研究可能有助于化学品和材料的先进制造，因为研究人员可能会开发出更有选择性的合成方法（更少的副产品）。Bertran教授的实验室与法国国家科学研究中心（CNRS）合作。加州大学圣地亚哥分校和cnrs关联大学之间的本科生和毕业生交流使学生能够在化学生产和劳动力发展方面发展国际视野。单配位碳可以被分离的想法是在氨基取代基的发现之后产生的，这种取代基减轻了碳烯进行二聚化和其他反应的内在倾向。在此基础上，制备了分别具有6个、5个和4个价电子的单配位氨基碳离子（R2NC）、氨基碳炔（R2NC）和氨基碳离子（R2NC+）。由于低配位主基化合物的重要性，合成了分别与单配位氨基碳离子和氨基碳离子等电子的氨基膦烯（R2NP）和氨基氨基乙烯（R2NB）。一些目标物种是不可分离的。尽管如此，对这些高风险、高回报的追求导致了原位生成类似物的新方法。碳烯可以同时形成两个sigma键，而单配位化合物可以同时形成三个sigma键，这一事实开辟了一种新的化学反应模型。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Carbon is the building material upon which the elements of life (DNA, RNA, etc.) are constructed. Carbon generally forms four chemical bonds. In this project funded by the Chemical Synthesis Program of the Chemistry Division, Professor Guy Bertrand of the Chemistry and Biochemistry Department at the University of California – San Diego (UCSD), seeks to prepare compounds that violate the four-bond rule. The isolation of such new carbon species has been impeded by the belief that they are inherently unstable. Professor Bertrand’s laboratory has recently developed new methods to prepare compounds called carbenes, which contain only two bonds to carbon. These methods are extended to carbynes, compounds in which carbon contains only a one bond. The availability of these species leads to better understanding of how chemical reactions of carbon take place, which then permits control of the reactivity of carbon-containing species. Ultimately, this research may help in the advanced manufacturing of chemicals and materials as researchers may develop more selective approaches to synthesis (fewer by-products). The Professor Bertran's laboratory collaborates with the French Le Centre National de la Recherche Scientifique (CNRS). The exchange of undergraduates and graduates between UCSD and CNRS-associated universities enables the students to develop an international perspective on chemical production and workforce development.The idea that monocoordinated carbon species may be isolable followed the discovery of amino substituents that mitigated the intrinsic tendency of carbenes to undergo dimerization and other reactions. Building on this idea, monocoordinated aminocarbanions (R2NC), aminocarbynes (R2NC), aminocarbocations (R2NC+), which feature six, five and four valence electrons, respectively, are prepared. Due to the importance of low coordinate main group compounds, aminophosphinidenes (R2NP) and aminoborylenes (R2NB), which are isoelectronic with the monocoordinated aminocarbanions and aminocarbocations, respectively, are synthesized. Some of the targeted species are non-isolable. Nonetheless, the pursuit of these high risk, high reward leads to new methodologies for in situ generated analogues. The fact that carbenes can simultaneously form two sigma bonds and monocoordinated compounds may form three opens a new model of chemical reactivity.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.