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

这项研究是基于我们实验室的两个令人兴奋的发现。在2014年，我们证明了NHC在黄金上形成单层，可以承受前所未有的极端热量，氧化剂，酸和碱。这项工作被国际专家称为“改变游戏规则”，包括芬兰纳米科学中心主任Hä kkinen。其他专家称之为“新的黄金标准”和“优雅”。已知NHC在过渡金属络合物中形成强键，但以前没有被检查为金属上自组装单层的硫醇的替代品。在本提案中，我们将探讨这一新颖而令人兴奋的发现的许多方面，包括：（1）NHC结构对膜质量和结合强度的影响，（2）使用NHC在包括Ag和Cu的其它金属上形成膜，其中NHC涂层可以帮助防止氧化和失泽，以及（3）在幻数Au簇中使用NHC，其是显著的分子材料，这些材料主要是用硫醇配体制备的，因此NHC将提供一种全新类型的纳米材料。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改性剂。该项目的许多合作已经到位，包括霍顿（表面科学，皇后），姆克林（STM成像，皇后物理），巴德利（STM成像，圣安德鲁斯），克拉茨（电化学，T疤痕U。），Hä kkinen（Theory，Finland）、Mosey（Theory，Queen's）和Tsukuda（nanoclusters，Japan）。 该提案的第二部分建立在催化的最新发现的基础上，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transmetalate到Pd的能力进行选择性的正交偶联。这种没有保护基团的背靠背Suzuki偶联在我们的Nature Comm.论文（修订版）之前从未完成过。在本研究计画中，我们将研究金属转移反应立体化学中的控制元素。我们将采用更复杂的耦合合作伙伴包含亲核试剂和亲电试剂，并将研究脱硼作为一种全新的方法制备手性硼化合物作为关键的起始材料，这种转变。该项目的各个方面将与Chirik（普林斯顿）合作。 学生的工资是拟议预算的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，因此为合作访问分配了资金。我计划继续为所有博士生提供在学位期间出国进行研究的机会。这对我的HQP扩展经验，形成国际网络和为未来的工作/PDF职位建立联系非常成功。

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 Hä kkinen, 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.), Hä kkinen (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.