sp-Hybridized carbon as a building block in the synthesis of molecules and materials

sp-杂化碳作为分子和材料合成的构建模块

• 批准号: RGPIN-2017-05052
• 负责人: Tykwinski, Rik
• 金额: $ 10.13万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709124
• 关键词: sp; Hybridized; carbon; building; block

Introduction. This proposal outlines synthetic routes to carbon-rich molecules with defined structure using sp-hybridized carbon as a key building block. These molecules are designed to give answers to both fundamental and applied questions in chemistry, as well as physics and materials science. This program follows a “physical organic chemistry” approach: We examine detailed relationships between chemical structure and molecular reactivity/properties, commonly via thermal analyses, electrochemical methods, X-ray crystallography, as well as NMR, emission, and absorption spectroscopies (EPR, vibrational, and transient absorption spectroscopies are used via collaboration). Often, our molecules are designed to answer specific questions posed by collaborators in, for example, molecular electronics and solar energy capture. The proposed research program relies on four interrelated themes. 1. Acetylene based structures. We will develop new strategies for the synthesis of conjugated polyynes to serve as functional materials and to model the properties of carbyne (the carbon allotrope constructed of sp-hybridized carbon). As high-energy molecules, polyynes are particularly challenging targets, and we will explore new stabilization schemes to meet these challenges. Supramolecular strategies are a specific focus, through synthesis of rotaxanes. Rotaxination is a key design motif, since it allows functionalization at the ends of a polyyne, e.g., for attaching molecular wires to electrodes or forming donor-acceptor polyynes. 2. Cumulene based structures. [n]Cumulenes (n is the number of cumulated double bonds) provide an alternative structure toward understanding the properties of carbyne. Many chemical, electronic, and optical properties for [n]cumulenes are currently unknown, and we intend to answer seminal questions concerning bonding in cumulenes, such as rotational barriers and bond length alternation. Cumulenes will also be used as reactive precursors to form carbon-rich architectures and polymers via a new topochemical polymerization reaction. 3. Molecular wires. We will explore and optimize cumulenes and polyynes to function as molecular wires. Endgroups are chosen to facilitate binding to electrodes such as gold and graphene. This project benefits distinctly from stabilization of polyynes and cumulenes as rotaxanes (Parts 1 and 2), which mimic insulated molecular wires. 4. Synthetic carbon allotropes: Graph(di)yne structures. The solution-state synthesis carbon allotropes composed of sp- and sp2-hybridized carbon (graphyne and graphdiyne), is difficult due to a lack of selectivity during polymerization. We will use a templated approach based on new building blocks derived from triethynylmethanol (TEtM). TEtMs can be easily varied at the termini of the alkynes and the alcohol “leaving group” toward optimizing binding and reactivity on metals.

导论.该提案概述了使用sp-杂化碳作为关键构建块来合成具有确定结构的富碳分子的路线。这些分子旨在回答化学、物理学和材料科学中的基础和应用问题。该计划遵循“物理有机化学”方法：我们研究化学结构和分子反应性/性质之间的详细关系，通常通过热分析，电化学方法，X射线晶体学，以及NMR，发射和吸收光谱（EPR，振动和瞬态吸收光谱通过合作使用）。通常，我们的分子设计用于回答合作者提出的特定问题，例如分子电子学和太阳能捕获。该研究计划基于四个相互关联的主题。 1.乙炔基结构。我们将开发新的策略合成共轭多炔作为功能材料，并模拟碳炔（sp-杂化碳构成的碳同素异形体）的性质。作为高能量分子，多炔是特别具有挑战性的目标，我们将探索新的稳定方案，以满足这些挑战。超分子策略是一个具体的焦点，通过合成轮烷。旋转化是一个关键的设计主题，因为它允许在多炔的末端官能化，例如，用于将分子线连接到电极或形成供体-受体多炔。 2.基于Cumulene的结构。[n]累积多烯（n是累积双键的数量）提供了一种理解碳炔性质的替代结构。[n]累积物的许多化学、电子和光学性质目前尚不清楚，我们打算回答有关累积物中成键的开创性问题，例如旋转垒和键长变化。累积多烯也将被用作反应前体，通过新的拓扑化学聚合反应形成富碳结构和聚合物。 3.分子导线。我们将探索和优化累积多烯和多炔作为分子导线。选择端基以促进与电极如金和石墨烯的结合。这个项目的好处明显从稳定的多炔和cumulenes轮烷（第1部分和第2部分），模仿绝缘分子线。 4.合成碳同素异形体：图（二）炔结构。由sp-和sp2-杂化碳（石墨炔和石墨二炔）组成的碳同素异形体的溶液状态合成由于在聚合期间缺乏选择性而困难。我们将使用基于来自三乙炔基甲醇（TEtM）的新构建块的模板化方法。TEtM可以容易地在炔和醇“离去基团”的末端变化，以优化对金属的结合和反应性。