Supramolecular Chemistry with Heavy Main-Group Elements

重主族元素的超分子化学

• 批准号: RGPIN-2022-05232
• 负责人: VargasBaca, Ignacio
• 金额: $ 2.11万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=748257
• 关键词: Supramolecular; Chemistry; Heavy; Main; Group

Supramolecular chemistry seeks understanding and application of the forces between molecules. The ultimate example of a supramolecular system is a living entity, in which a multitude of molecules are organized into exquisitely self-assembled structures and perform an astonishing symphony of chemical and physical processes. The more modest systems studied by chemists in the laboratory have been primarily based on a handful of supramolecular interactions, namely hydrogen bonding, coordination of metal ions, and stacking of flat structures made from carbon atoms. However, other intermolecular interactions are just beginning to be investigated in detail. My research group at McMaster has pioneered in Canada the systematic investigation of "Chalcogen Bonding" (ChB), which is the interaction between electron-rich atoms and atoms of the chalcogens (the heavy members of the oxygen family of the periodic table) that are avid for negative electric charge. Typical ChB interatomic distances are much longer than "regular covalent" bonds and can be reversibly formed and broken with minimal structural changes of the interacting molecules. This phenomenon is analogous to hydrogen bonding, but more complex due to the nature of heavy atoms. Notably, ChB interactions have unique features that help tune the structure and physical properties of materials relevant to technological applications. Previous work by our group showed that ChB interactions lead to macroscopic optical properties such as chromotropism and can induce the growth of crystals with nonlinear optical properties. In contrast to other intermolecular interactions, ChB enables intermolecular electron mobility, a feature that can enable semiconductor properties and could be applied to build self-assembled molecular wires. Such conducting one-molecule thick structures are appealing to construct integrated circuits because, compared to all-silicon components, they should be less prone to current leaks. Here self-assembling molecules have a particular advantage: thermodynamics enables error self-correction, which solves the problem of occasional defects that are inevitable in the synthesis of oligothiophenes and other large organic molecules commonly used in the part of nanotechnology known as molecular electronics. Our overarching goal is to define methods to utilize ChBs in functional supramolecular structures. During the next grant period, we will expand the repertoire of ChB building blocks and self-assembled structures. While our investigations pursue a fundamental understanding, knowledge derived from this work is highly relevant to applications in industries as diverse as fine-chemical synthesis, optical information technologies, and electronics. Because this research program combines a wide variety of experimental and computational methods of modern chemistry, it constitutes an excellent vehicle to train highly qualified personnel for Canadian industry, national laboratories, and academia.

超分子化学寻求对分子之间力的理解和应用。超分子系统的最终例子是一个生命体，其中大量的分子被组织成精美的自组装结构，并演奏出令人惊叹的化学和物理过程的交响乐。化学家在实验室研究的更简单的系统主要基于一些超分子相互作用，即氢键、金属离子的配位以及由碳原子构成的平面结构的堆叠。然而，其他分子间相互作用才刚刚开始详细研究。我在麦克马斯特的研究小组在加拿大率先对“硫族键合”（ChB）进行系统研究，这是富电子原子与硫族元素原子（元素周期表氧族的重成员）之间的相互作用。热衷于负电荷。典型的 ChB 原子间距离比“常规共价”键长得多，并且可以可逆地形成和断裂，而相互作用分子的结构变化最小。这种现象类似于氢键，但由于重原子的性质而更加复杂。值得注意的是，ChB 相互作用具有独特的功能，有助于调整与技术应用相关的材料的结构和物理性质。我们小组之前的工作表明，ChB 相互作用会导致显色性等宏观光学特性，并且可以诱导具有非线性光学特性的晶体的生长。与其他分子间相互作用相比，ChB 能够实现分子间电子迁移率，这一特性可以实现半导体特性，并可用于构建自组装分子线。这种导电的单分子厚结构对于构建集成电路很有吸引力，因为与全硅元件相比，它们应该不易发生电流泄漏。在这里，自组装分子具有特殊的优势：热力学能够实现误差自我校正，这解决了低聚噻吩和分子电子学纳米技术部分常用的其他大型有机分子合成中不可避免的偶然缺陷问题。我们的首要目标是定义在功能性超分子结构中利用 ChB 的方法。在下一个资助期内，我们将扩大 ChB 构建模块和自组装结构的范围。虽然我们的研究追求的是基本理解，但从这项工作中获得的知识与精细化学合成、光学信息技术和电子等多种行业的应用高度相关。由于该研究项目结合了现代化学的多种实验和计算方法，因此它构成了为加拿大工业界、国家实验室和学术界培养高素质人才的绝佳工具。