Quadrupole Ion Trap and Tandem Quadrupole Mass Spectrometric Studies of Reactive Organic Species in the Gas Phase

这项有机和高分子化学的资助是在妇女研究机会计划的赞助下进行的。该奖项为普渡大学Hilkka KentTamaa博士的研究提供支持，该研究旨在表征气相中分子碎片的化学和物理性质。四极杆质谱仪将被用来测量有机分子的带电(阳离子)和中性(自由基)片段的反应性。了解分子碎片在气相中的反应性对于了解高层大气中发生的化学事件和了解溶剂化作用对溶液中发生的许多化学反应的影响都是重要的。将使用两种不同类型的四极质谱计：配备脉冲阀的离子陷阱和三重四极串联质谱仪。这两种技术的不同能力将被用于三个不同领域的研究。(I)研究无溶剂下酸催化环氧化物反应的机理和势能面。此外，计划进行的实验将产生中性环氧化物、质子化环氧化物及其异构体的热化学数据。(Ii)配位不饱和硼阳离子的相对稳定性和本征化学反应活性是一个令人感兴趣的话题。采用的实验将允许确定硼离子和各种其他含硼物种的生成热，包括中性偏硼酸衍生物和偏硼酸衍生物。(3)对电离叶立德和电离两性离子的双分子气相化学的研究将提供有关这些感兴趣的离子及其中性气相自由基和双自由基类似物的热化学和反应性的信息。

This grant in Organic and Macromolecular Chemistry is made under the auspices of the Research Opportunities for Women Program. The award provides support for research by Dr. Hilkka Kenttamaa, Purdue University, which is aimed at characterizing the chemical and physical properties of molecular fragments in the gas phase. Quadrupole mass spectrometry will be employed to measure reactivity of both charged (cationic) and neutral (radical) fragments of organic molecules. Understanding the reactivity of molecular fragments in the gas phase is important both for understanding chemical events which occur in the upper atmosphere, and for understanding the influence of solvation upon the many chemical reactions which occur in solution. Two different types of quadrupole mass spectrometers will be employed: an ion trap equipped with pulsed valves, and a triple quadrupole tandem mass spectrometer. The various capabilities of the two techniques will be utilized in studies on three different areas. (i) Mechanisms and potential energy surfaces of acid-catalyzed reactions of epoxides in the absence of solvents will be studied. In addition, experiments are planned which will yield thermochemical data for neutral epoxides, protonated epoxides and their isomeric forms. (ii) Relative stabilities and intrinsic chemical reactivity of coordinately unsaturated borocations are a topic of interest. The experiments employed will allow heats of formation to be determined for borenium ions and various other boron-containing species, including derivatives of neutral metaboric and metaboronic acids. (iii) Studies on bimolecular gas-phase chemistry of ionized ylides and ionized zwitterions will provide information concerning the thermochemistry and reactivity of these interesting ions as well as their neutral gas-phase radical and diradical analogs.