Thermochemistry and Kinetics of Polyatomic Free Radicals

古特曼教授得到了实验物理化学计划的资助，该计划研究涉及第二排元素的多原子自由基和卤素或卤化氢的基本反应的动力学和热化学。实验技术包括在受控条件下使用准分子激光光解产生自由基，以及监测反应物和产物的时间分辨实验。要研究的自由基包括卤代和全卤甲基基、含氧自由基、含氮自由基和不饱和碳氢自由基。对较重元素，特别是硅、磷、锗和砷的自由基反应的研究特别感兴趣，因为由于这些元素有能力处于比碳更高的价态，所以很可能会有新的化学路线对这些元素的自由基开放。本研究的目的是获得多原子自由基基元反应动力学和动力学的新的基础知识，并确定这些物种的重要热化学性质。本项目要研究的自由基对大气化学和燃烧很重要；卤代自由基与我们寻找破坏臭氧的氯氟烃的替代品有关。这项研究的一个令人兴奋的部分是对化学气相沉积(CVD)反应堆中可能涉及的磷、硅、砷和锗自由基化学的研究。化学气相沉积是用于生长半导体工业中用于制造微电子器件的薄膜和涂层的主要技术之一。

Professor Gutman is supported by a grant from the Experimental Physical Chemistry Program to study the kinetics and thermochemistry of elementary reactions involving polyatomic radicals of the second row elements and halogens or hydrogen halides. Experimental techniques include the use of excimer laser photolysis to produce the free radicals under controlled conditions and time-resolved experiments to monitor reactants and products. The radicals to be studied include halo- and perhalomethyls, oxygen containing radicals, nitrogen centered radicals and unsaturated hydrocarbon radicals. Studies of reactions of free radicals of the heavier elements, particularly radicals of silicon, phosphorus, germanium, and arsenic are of particular interest because it is likely that new chemical routes are open to radicals of these elements due to their ability to be in higher valence states than carbon. %%% The objectives of this research are to gain new fundamental knowledge of the kinetics and dynamics of elementary reactions of polyatomic free radicals and to determine important thermochemical properties of these species. The radicals to be studied in this project are important to atmospheric chemistry and combustion; the halogenated radicals are relevant to our search for replacements for the ozone-destroying chlorofluorocarbons. An exciting part of the research is the study of the chemistry of radicals of phosphorus, silicon, arsenic, and germanium which are likely to be involved in chemical vapor deposition (CVD) reactors. Chemical vapor deposition is one of the primary techniques used for growing thin films and coatings used in the semiconductor industry for the fabrication of microelectronic devices.