Structures of Non-Polar Molecules by High Resolution FT-IR Spectroscopy

通过高分辨率 FT-IR 光谱分析非极性分子的结构

• 批准号: 9207156
• 负责人: Norman Craig
• 金额: $ 5.09万
• 依托单位: Oberlin College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-06-01 至 1996-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9207156&HistoricalAwards=false
• 关键词: Structures; Non; Polar; Molecules; Resolution

In this RUI project in the Experimental Physical Chemistry Program of the Chemistry Division, Craig will use FTIR spectroscopy to obtain structures of several small, non-polar organic molecules. He will analyze the rotationally resolved IR spectra of the trans isomers and their isotopic species of several molecules which have higher electronic energies than their respective cis isomers. The structures will be compared with those of the cis isomers and will provide data for comparison with ab initio calculations. High resolution infrared spectra will be recorded on a spectrometer at the National Institute for Standards and Technology in the laboratory of Dr. Walter J. Lafferty. %%% There is a curious phenomenon called the "cis effect" in molecules with large substituent groups (which we will call X and Y) at either end of a rigid, planar carbon-carbon double-bonded skeleton, for example, HXC=CYH. In such molecules the isomeric structure in which the two large (X and Y) groups are on the same side (in the "cis" or near position) is energetically more stable than the structure in which the large groups are on opposite corners of the molecule (in the "trans" position). Intuitively, one would expect that the "cis" structure would be less stable energetically because the large groups can interfere with each other more readily. This current project will acquire data which will allow theoretical studies to be compared with experimental structures in order to test the validity of the theoretical models. It is expected that a successful theory will help explain this curious "cis effect" anomaly.

在化学系实验物理化学项目的 RUI 项目中，克雷格将使用 FTIR 光谱来获得几种小非极性有机分子的结构。 他将分析反式异构体的旋转分辨红外光谱以及几种分子的同位素种类，这些分子的电子能量比各自的顺式异构体更高。 该结构将与顺式异构体的结构进行比较，并提供与从头计算进行比较的数据。 高分辨率红外光谱将在美国国家标准与技术研究所 Walter J. Lafferty 博士实验室的光谱仪上记录。 %%% 在刚性平面碳碳双键骨架两端具有大取代基（我们称之为 X 和 Y）的分子中存在一种奇怪的现象，称为“顺式效应”，例如 HXC=CYH。 在此类分子中，两个大基团（X和Y）位于同一侧（“顺式”或附近位置）的异构结构在能量上比大基团位于分子对角（“反式”位置）的结构更稳定。 直觉上，人们会认为“顺式”结构在能量上不太稳定，因为大基团更容易相互干扰。 当前的项目将获取数据，将理论研究与实验结构进行比较，以测试理论模型的有效性。 预计一个成功的理论将有助于解释这种奇怪的“顺式效应”异常现象。