Accession Number : AD1026495

Title :   Potential Energy Surfaces and Dynamics of High Energy Species

Descriptive Note : Technical Report,01 Oct 2005,30 Sep 2008

Corporate Author : Iowa State University Ames United States

Personal Author(s) : Gordon,Mark S

Full Text :

Report Date : 13 Apr 2009

Pagination or Media Count : 29

Abstract : Several papers on ionic liquids have been published or submitted as a result of this grant. The first set of papers used second order perturbation theory to study the geometries and substituent effects of the cations commonly employed in energetic ionic liquids. These are variously substituted triazolium, tertazolium, and pentazolium cations. The heats of formation of all species were predicted using G2 and G3 theory. It was consistently found that the most energetic substituents are -CN and - N3. When one cation is combined with one anion, proton transfer almost always occurs with no intervening energy barrier, yielding a neutral pair. When two ion pairs are considered, conceptually similar to the face of a crystal, the ion separated species is predicted to be 6 kcal/mol lower in energy than the double proton transferred neutral species. These calculations were done using coupled cluster theory, but this level of theory is too expensive to study larger clusters. Therefore, we have turned to the fragment molecular orbital method, which can retain the accuracy of full electronic structure theory calculations, while greatly reducing the cost.

Descriptors :   ionic liquids , electronic structure theory , MODELS , electronic structure methods , potential energy , high energy

Subject Categories : Inorganic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE