Novel Catalytic Transformations of Organoboron Species and the Development of Ultrastable Self-Assembled Monolayers on Metal Surfaces

这项拟议的研究是基于我们实验室的两项令人兴奋的发现。2014年，我们证明了NHC在黄金上形成了单分子膜，可以经受前所未有的极端高温、氧化剂、酸和碱。这项工作被包括芬兰纳米科学中心主任哈基宁在内的国际专家称为“改变游戏规则”。其他专家称其为“新金本位”和“高雅”。已知NHC在过渡金属络合物中形成强键，但以前还没有被研究过作为金属表面自组装单分子膜的硫醇替代品。在这个提议中，我们将探索这一新颖而令人兴奋的发现的许多方面，包括：(1)NHC结构对薄膜质量和结合强度的影响，(2)NHC用于在包括银和铜在内的其他金属上成膜，其中NHC涂层可以帮助防止氧化和变色，以及(3)NHC在幻数Au团簇中的使用，这是一种了不起的分子材料，主要是用硫醇配体制备的，因此NHCS将提供一种全新的纳米材料。在长期目标中，我们将(4)探索NHC在分子电子学中的应用，以及作为催化活性表面和纳米颗粒的修饰剂。这个项目的许多合作已经到位，包括与Horton(表面科学，女王的)，McLean(STM成像，女王物理学)，Baddeley(STM成像，圣安德鲁斯)，Kraatz(电化学，T SCAR.)，Häkkinen(理论，芬兰)，Mosey(理论，女王的)和Tsukuda(纳米团簇，日本)。*该提议的第二部分建立在最近的催化发现的基础上，我们证明了具有几乎相同的硼取代基的有机分子可以通过操纵C-B键的转移到Pd的能力来进行选择性的、正交的偶联。在我们的自然通讯之前，这种没有保护基团的背靠背铃木耦合从未完成过。论文(修订中)。在这项资助中，我们将研究转金属反应立体化学中的控制元素。我们将使用包含亲核剂和亲电剂的更复杂的偶联伙伴，并将研究脱甲基化作为一种全新的方法来制备手性硼化合物，作为这一转化的关键起始材料。这个项目的方方面面将与奇里克(普林斯顿)合作。*学生工资是拟议预算的70%，这代表了我对培训的重大承诺。拟议的化学比以前的项目更具多学科性质，因此为协作访问分配了资金。我计划继续为所有博士生提供在攻读学位期间出国进行研究的机会。这非常成功地拓宽了我总部的经验，形成了国际网络，并为未来的工作/PDF职位建立了联系。**

The proposed research is based on two exciting discoveries from our lab. In 2014, we demonstrated that NHCs form monolayers on gold that withstand unprecedented extremes of heat, oxidant, acid and base. This work was called "game changing" by international experts, including Häkkinen, director of the Nanoscience Centre in Finland. Other experts called it "the new gold standard" and "elegant". NHCs have been known to form strong bonds in transition metal complexes but had not previously been examined as alternatives to thiols for self-assembled monolayers on metals. In this proposal, we will explore many aspects of this novel and exciting discovery, including: (1) the effect of NHC structure on film quality and bond strength, (2) the use of NHCs to form films on other metals including Ag and Cu where the NHC coating may help prevent oxidation and tarnishing, and (3) the use of NHCs in magic number Au clusters, which are remarkable molecular materials, that have been largely prepared with thiol ligands and thus NHCs will provide a completely new type of nanomaterial. In long term goals, we will (4) explore the use of NHCs in molecular electronics and as modifiers for catalytically active surfaces and nanoparticles. Many collaborations for this project are already in place, including with Horton (surface science, Queen's), McLean (STM imaging, Queen's Physics), Baddeley (STM imaging, St. Andrews), Kraatz (Electrochemistry, U of T Scar.), Häkkinen (Theory, Finland), Mosey (Theory, Queen's) and Tsukuda (nanoclusters, Japan).***The second part of this proposal builds on recent discoveries in catalysis, where we demonstrated that organic molecules with practically identical boron substituents can undergo selective, orthogonal coupling by manipulating the ability of the C–B bond to transmetalate to Pd. This back-to-back Suzuki coupling without protecting groups had never been accomplished prior to our Nature Comm. paper (in revision). In this grant, we will study the control elements in the stereochemistry of the transmetalation reaction. We will employ more complex coupling partners containing both a nucleophile and an electrophile, and will study deborylation as a completely novel method for the preparation of chiral boron compounds as critical starting materials for this transformation. Aspects of this project will be collaborative with Chirik (Princeton). ******Student salaries are 70% of the proposed budget, representing my significant commitment to training. The proposed chemistry is even more multidisciplinary than previous projects and thus funds are allocated for collaborative visits. I plan to continue to provide all PhD students the opportunity to carry out research abroad during their degree. This has been highly successful for broadening the experience of my HQP, forming international networks and making contacts for future job/PDF positions.**