US-Federal Republic of Germany Cooperative Research: Struc- tural Studies of Very Unstable Compounds of Theoretical Interest by Low Temperature X-ray Crystallography

该奖项支持莱斯大学的W. E. Billups教授与西德埃森大学无机化学研究所的Roland Boese博士合作进行研究。他们联合研究的目的是确定具有理论意义的非常不稳定分子的结构。Boese博士和他的同事们开发了一种装置，通过聚焦红外光的微型区域熔化程序，在低温下在x射线衍射仪上使液体结晶。他已经能够非常精确地测定不稳定的无机化合物的结构。比卢普斯博士开发了一种真空气相法，用于合成小环环烷烃和其他高张力有机化合物。他们引进的创新实验技术具有广泛但不同的适用性。合作计划结合了他们几乎独特的专业知识，通过在莱斯大学合成和初步表征化合物，然后使用埃森不寻常的设备确定它们的精确结构。小环环烷烃由于其相对于非环异构体的高能量含量往往导致意想不到的性质而引起了人们的极大兴趣。由于对这种高度不稳定的化合物进行结构分析极其困难，这一领域的进展一直很缓慢。Boese技术在低温x射线晶体学中获得良好结构数据的成功应用，对于从事结构化学的物理有机化学家来说是一个福音。此外，该技术一旦进入整个化学社区，将在小不稳定分子的结构分析中得到广泛应用。

This award supports Professor W. E. Billups of Rice University to collaborate in research with Dr. Roland Boese of the Institute for Inorganic Chemistry of the University of Essen, West Germany. The objective of their joint research is to determine the structures of very unstable molecules of theoretical interest. Dr. Boese and his co-workers have developed an apparatus to crystallize liquids on an x-ray diffractometer at low temperatures by means of a miniature zone melting procedure with focused infrared light. He has been able to determine very accurate structures of unstable inorganic compounds. Dr. Billups has developed a vacuum gas phase procedure for the synthesis of small ring cycloalkanes and other highly strained organic compounds. The innovative experimental techniques they have introduced have had wide but separate applicability. The plan for the collaboration combines their virtually unique expertise through the synthesis and preliminary characterization of the compounds at Rice University and then determination of their precise structures using the unusual equipment at Essen. Small ring cycloalkanes have aroused great interest because their high energy content relative to their acyclic isomers often results in unexpected properties. Progress in this area has been slowed by the extreme difficulty of structural analysis of such highly unstable compounds. The successful application of the Boese technique to the acquisition of good structural data by low temperature x-ray crystallography would be a boon to physical organic chemists engaged in structural chemistry. In addition, the technique, once accessible to the chemical community as a whole, will find wide application in the structural analysis of small unstable molecules.