Exploratory Syntheses of Borometallic Molecular Wheels and Borospherenes

非技术总结：EAGER的这一提议旨在使用液相中的激光烧蚀以固体形式合成新型硼基纳米团簇的原理验证。如果概念验证的努力是成功的，使用湿化学的更好的合成路线可能会被发现，以提高合成产率。开发这些新型硼纳米结构的有效大规模合成方法将代表材料科学的重大进展。散装形式的硼纳米结构将提供具有潜在有趣的电子，磁性和催化性能的新材料。EAGER项目还将为跨学科的本科生和研究生提供研究培训。技术总结：在过去的十年中，对尺寸选择的硼簇的研究导致了各种有趣的纳米结构，从平面簇到硼烯和硼球烯。硼苯（或原子薄硼层）最近已经在银基底上合成作为一类新的2D材料。这个EAGER项目旨在探索以固体形式的硼球烯（全硼笼状簇）以及以过渡金属为中心的硼环型簇M©Bn（n = 8-10）的本体合成，这是芳香族硼杂环分子轮。由于硼的缺电子性质，硼杂环戊二烯簇和硼杂环戊二烯的边缘或表面原子具有空的2 p轨道，并且预期与刘易斯碱类型的配体（例如酰胺或膦）反应，所述配体将用于保护簇。将通过在含有适当配体的溶液中激光烧蚀适当的硼/金属复合物或纯硼靶来产生M©Bn型簇和硼球烯。配体将与初生硼纳米团簇配位以允许它们的分离和随后的结构和性质表征。激光烧蚀也可以在溶液外部进行，然后可以捕获新生的簇。合成方法将是物理和化学方法的结合，不像富勒烯合成方法是完全物理方法（He中的碳弧）。

Non-Technical Summary: This EAGER proposal is aimed at proof-of-principle syntheses of novel boron-based nanoclusters in solid forms using laser ablation in the liquid phase. If the prove-of-concept efforts are successful, better synthetic route using wet chemistry may be found to improve the synthetic yields. Development of effective large-scale synthetic methods of these novel boron nanostructures would represent significant advances in materials science. The boron nanostructures in bulk form will provide new classes of materials with potentially interesting electronic, magnetic, and catalytic properties. The EAGER project will also provide research training for undergraduate and graduate students across disciplines. Technical Summary: Studies on size-selected boron clusters over the past decade have led to a variety of interesting nanostructures from planar clusters to borophenes and borospherenes. Borophenes (or atomic thin boron layers) have recently been synthesized on silver substrates as a new class of 2D materials. This EAGER project seeks to explore bulk syntheses in solid forms of borospherenes (all-boron cage clusters), as well as transition metal centered boron ring type clusters, M©Bn (n = 8-10), which are aromatic borometallic molecular wheels. Due to the electron deficient nature of boron, the edge or surface atoms of the borometallic clusters and borospherenes have empty 2p orbitals and are expected to be reactive with Lewis base types of ligands, such as amides or phosphines, which will be used to protect the clusters. The M©Bn type clusters and borospherenes will be produced by laser ablation of appropriate boron/metal composite or pure boron targets in solutions, which contain the appropriate ligands. The ligands will coordinate to the nascent boron nanoclusters to allow their isolation and subsequent structural and property characterization. The laser ablation can also take place outside the solution, which can then capture the nascent clusters. The synthetic method will be a combination of physical and chemical approach, unlike the fullerene synthetic method, which is a completely physical method (carbon arc in He).