Organic Ion-Molecule Chemistry

点击翻译按钮获取中文摘要

Organic ion/molecule reactions will be explored in the gas phase with a Fourier transfolm mass spectrometer and a variable temperature flowing afterglow-triple quadrupole apparatus (190 C to 400 C). The results will be contrasted to those in condensed media and supplemented with ab initio molecular orbital and density functional theory calculations. Particular attention will be focused on antiaromatic compounds, reactive intermediates, and zwitterionic ions. Previously, long-lived cyclopropenyl anions were generated in the gas phase and solution. These species in general are discussed in all introductory organic chemistry textbooks because they are of fundamental interest and may serve as potential sources of novel materials. During this grant period, spectroscopically characterizing cyclopropenyl anion derivatives and probing their reactivities and structures are planned. The energetics of a variety of antiaromatic and homoantiaromatic compounds (ions and neutrals) also will be obtained so that these long sought after but elusive species can be better understood. Reactive intermediates play a central role in understanding chemical reactions and considerable emphasis will be placed on studying their reactivity and energetics. Some technologically important intermediates will be examined in addition to a number of strained ring compounds. Much of this work will be facilitated by the recent development of a general and highly selective method for preparing radical anions in the gas phase. Finally, electrostatic effects will be examined. These interactions are extraordinarily important in a wealth of areas ranging from organic synthesis, material design and chromatography, to molecular recognition, enzyme structure, and drug development. Recently, the first zwitterionic ion and its neutral counterpart in the gas phase were prepared. This makes it possible to explore the structure, reactivity, and energetics of dipolar ions, develop models to explain zwitterionic species, and obtain a much better understanding of electrostatic effects.With this Accomplishment-Based Renewal award the Organic and Macromolecular Chemistry Program supports the ongoing work of Professor Steven R. Kass at the University of Minnesota- Twin Cities. The research focuses on understanding the reactivities and thermodynamic properties of reactive organic intermediates. The work will be of interest to chemists trying to understand the fundamental factors which control several types of reactions in gases and liquids, and will provide valuable research training to both graduate and undergraduate students.