Thermochemistry and Kinetics of Polyatomic Free Radicals

古特曼教授获得了实验物理化学计划的资助，研究涉及第二行元素和卤素或卤化氢的多原子自由基的基本反应的动力学和热化学。实验技术包括使用准分子激光光解在受控条件下产生自由基和时间分辨实验来监测反应物和产物。研究的自由基包括环甲基和准甲基、含氧自由基、氮中心自由基和不饱和烃自由基。对重元素自由基反应的研究，特别是硅、磷、锗和砷的自由基的反应是特别有趣的，因为由于这些元素的原子价态比碳的原子价态高，很可能为这些元素的自由基开辟了新的化学途径。本研究的目的是获得关于多原子自由基基本反应动力学和动力学的新基本知识，并确定这些物质的重要热化学性质。本项目研究的自由基对大气化学和燃烧具有重要意义；卤化自由基与我们寻找破坏臭氧层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磷、硅、砷和锗的自由基的化学研究，这些自由基很可能与化学气相沉积（CVD）反应器有关。化学气相沉积是半导体工业中用于微电子器件制造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.