Computational and matrix isolation studies of tetra-tert-butylethane

Bucher, G. (2009) Computational and matrix isolation studies of tetra-tert-butylethane. European Journal of Organic Chemistry(25), pp. 4340-4345. (doi: 10.1002/ejoc.200900378)

Abstract

Irradiation of cryogenic xenon matrices containing the sterically congested alkane tetra-<i>tert</i>-butylethane (<b>1</b>) with intense pulses from a KrF excimer laser (λ_exc) = 248 nm) have resulted in the formation of methane and isobutene as the major products. Larger fragments derived from <b>1</b>, such as 2,2-dimethylbutane (<b>10</b>), were also detected, whereas no evidence was obtained for the formation of the elusive tetra-<i>tert</i>-butylethylene (<b>2</b>). The results suggest that biphotonic irradiation of xenon matrices containing <i>tert</i>-butylated precursor molecules may generally result in the efficient formation of isobutene and smaller alkanes. An analysis of the decomposition reactions of <b>1</b> by various computational methods revealed that commonly used DFT methods, such as B3LYP or BLYP, and MP2 theory do not provide a good description of the energetics of the decay reactions of the sterically overloaded alkane <b>1</b>. The recently developed M05-2X method was the only method among those tested to yield an activation enthalpy for the cleavage of <b>1</b> in agreement with the experimental value.

• Item Type: Articles
• Keywords: Activation, alkanes, alkenes, CO, computer chemistry, decomposition, Density-functional theory, efficient, forces, Matrix isolation, Methane, molecule, molecules, spectroscopy, Strained molecules, Thermochemistry, thermolabile hydrocarbons, Xenon, Xenon matrix
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Bucher, Dr Goetz
• Authors: Bucher, G.
• Subjects: Q Science > QD Chemistry; Q Science > QC Physics
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: European Journal of Organic Chemistry
• Publisher: Wiley - V C H Verlag GmbH & Co. KGaA
• ISSN: 1434-193X
• ISSN (Online): 1099-0690
• Published Online: 17 July 2009