Isotope Enrichment Via Electron Attachment

这个项目代表了有机动力学项目对伊利诺伊州立大学的杰拉尔德·R·史蒂文森和理查德·C·赖特的研究的持续支持。这项工作涉及在中性化合物和它们的带负电荷的化合物之间建立平衡。由于平衡位置随特定的同位素而变化，这导致了一种新的同位素分离方法。这项研究旨在开发一种可用于分子同位素异构体分离的热力学方案。伊利诺伊州立大学的研究小组以前观察到，只有当一个或多个原子被不同的同位素原子取代时，共轭有机材料的溶液状态和固态电子亲和能发生相当大的变化(高达数百卡/摩尔)。这意味着有机同位素异构体(如二苯甲酮和二苯甲酮-O-18)在溶液中因碱金属摩尔量不足而被还原，将导致两个同位素异构体之间竞争添加的电子。由于两种材料的溶液电子亲和势不同，O-18同位素的部分浓缩可以像分离自由基阴离子和中性分子一样容易实现。将对包括C-13、O-18和N-15在内的各种同位素探索这种同位素浓缩方法。此外，还将建立一个统计热力学模型，该模型可用于预测同位素异构体之间电子交换的平衡常数。

This project represents continuing support by the Organic Dynamics Program for the research of Gerald R. Stevenson and Richard C. Reiter of Illinois State University. The work involves the establishment of equilibria between neutral compounds and their negatively charged counterparts. Since the position of equilibrium varies with particular isotopes, this has led to a new method for isotope separation. This research is directed at developing a thermodynamic scheme that can be utilized for the separation of molecular isotopic isomers. The Illinois State group has previously observed that the solution state and solid state electron affinities of conjugated organic materials differing only by the substitution of one or more atoms with isotopically different atoms experience rather dramatic (up to several hundred cal/mol) changes. This means that the reduction of organic isotopic isomers (e.g., benzophenone and benzophenone-O-18) with deficient molar amounts of alkali metal in solution will result in a competition between the two isotopic isomers for the added electrons. Since the solution electron affinities of the two materials are not the same, the partial enrichment of the O-18 isotope can be achieved as easily as separating the radical anions from the neutral molecules. This method of isotope enrichment will be explored for a variety of isotopes including C-13, O-18 and N-15. Further, a statistical thermodynamic model will be developed that can be utilized to predict the equilibrium constants for electron exchange between the isotopic isomers.