Chemistry with a tiny hammer - cleaving the C-H bonds of adsorbed organic molecules with hyperthermal protons

用小锤子进行化学——用高温质子裂解吸附有机分子的 C-H 键

• 批准号: 327221-2006
• 负责人: Lau, Leo
• 金额: $ 2.8万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=397641
• 关键词: Chemistry; tiny; hammer; cleaving; bonds

This proposal aims at exploring my concept of performing chemistry with a tiny hammer - a hyperthermal proton, for the synthesis of novel polymer films.  Recently my research team showed that when adsorbed hydrocarbon molecules are bombarded by 10eV protons, the energy transfer is effective in H-H collisions but ineffective in H-C collisions.  Such a difference in kinematics leads to the cleavage of C-H bonds with no C-C bond breakage.  The adsorbed hydrocarbon molecules are thereby cross-linked into an ultrathin polymer film.  In the next five years, we will further clarify the nature and reaction mechanisms of this method and its scope of applicability towards the production of novel polymer films having tailor-made physical and chemical properties.  To study the reaction mechanisms, we will analyze species emitted from adsorbed precursor molecules during ion bombardment as a function of ion energy and ion type (H+, D+, and He+).  We will compare these data with those collected from surface analysis of the bombarded samples.  To explore the applications of the proposed hyperthermal proton method, we will use it to cleave C-H bonds of conjugated semiconducting polymer films and thereby to increase the average conjugated chain length with the induced cross-linking.  Normally as-deposited conjugated polymer films are thermally cured to increase cross-linking and electrical conductivity. The proposed proton treatment provides an attractive alternative as it is a dry process with no heating requirement.  In addition to this application, we will use the method to cross-link unsaturated and aromatic organosilane self-assembly monolayers on conductive substrates such as n-TiO2, for the development of molecular electronics.   We have already paved the ground work and confirmed the feasibility of our proposed approaches. Therefore, we are confident that if the proposed project is approved, we will produce original results bearing both scientific and technological impacts, and train highly qualified personnel in this market-driven field.

这个提议旨在探索我用一个小锤子--一个超热质子--来进行化学操作来合成新型聚合物薄膜的概念。最近，我的研究小组发现，当吸附的碳氢分子被10 eV的质子轰击时，能量转移在H-H碰撞中是有效的，但在H-C碰撞中无效。这样的运动学差异导致C-H键的断裂，而不是C-C键的断裂。吸附的碳氢分子因此被交联成超薄的聚合物薄膜。预计在未来五年，我们将进一步阐明这种方法的性质和反应机理，以及它在生产具有定制的物理化学性质的新型聚合物薄膜方面的适用范围。为了研究反应机理，我们将分析离子轰击过程中被吸附的前体分子释放的物种作为离子能量和离子类型(H+、D+和He+)的函数。我们将这些数据与从轰击样品的表面分析中收集的数据进行比较。为了探索所提出的超热质子方法的应用，我们将利用它来裂解共轭半导体聚合物薄膜的C-H键，从而通过诱导交联来增加平均共轭链长。通常情况下，沉积时的共轭聚合物薄膜会进行热固化，以增加交联性和导电性。建议的质子处理提供了一个有吸引力的替代方案，因为它是一个不需要加热的干燥过程。除了这一应用之外，我们还将使用这种方法在n-Ti02等导电衬底上交联不饱和和芳香族有机硅烷自组装单分子膜，用于分子电子学的开发。*我们已经铺平了基础工作，并确认了我们提出的方法的可行性。因此，我们有信心，如果拟议的项目获得批准，我们将产生具有科技影响的原创成果，并在这个市场驱动的领域培养高素质的人才。