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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=667344
• 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.

导言。这项提案概述了使用sp型杂化碳作为关键构建块来合成具有特定结构的富碳分子的路线。这些分子的设计目的是为化学、物理和材料科学中的基础和应用问题提供答案。这项计划遵循“物理有机化学”的方法：我们通常通过热分析、电化学方法、X射线结晶学以及核磁共振、发射和吸收光谱(EPR、振动和瞬时吸收光谱通过协作使用)来研究化学结构和分子反应性/性质之间的详细关系。通常，我们的分子是为回答合作者提出的具体问题而设计的，例如，分子电子学和太阳能捕获。拟议的研究计划依赖于四个相互关联的主题。*1.基于乙炔的结构。我们将开发新的策略来合成作为功能材料的共轭聚炔，并对卡宾(由SP杂化碳构建的碳同素异形体)的性质进行模拟。作为高能分子，聚炔是特别具有挑战性的目标，我们将探索新的稳定方案来应对这些挑战。超分子策略是一个特别的焦点，通过合成轮烷来实现。轮烷化是一个关键的设计基序，因为它允许在聚炔的末端进行官能化，例如，用于将分子线连接到电极上或形成给体-受体多炔。*2.异丁烯结构。[n]Cumulenes(n是累积双键的数目)为理解卡宾的性质提供了另一种结构。[n]积累烯的许多化学、电子和光学性质目前尚不清楚，我们打算回答有关积累烯成键的开创性问题，如旋转势垒和键长变化。Cumulenes还将被用作反应前驱体，通过一种新的拓扑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烯和聚炔作为分子线的功能。选择端基是为了促进与金和石墨烯等电极的结合。这个项目明显受益于聚炔和累积烯作为轮烷的稳定化(第一部分和第二部分)，它模仿绝缘分子导线。*4.合成碳同素异形体：图(双)因结构。由sp2和sp2杂化的碳(石墨烯和石墨烯)组成的溶液相合成碳同素异形体，由于在聚合过程中缺乏选择性而变得困难。我们将使用基于来自三乙炔甲醇(TETM)的新构建块的模板化方法。可以很容易地在炔烃和醇的末端改变TETM，以优化金属上的结合和反应活性。