Thermodynamic Stability of Trichlorocyclopropenyl Cation. An Experimental (FTICR) and Computational [G2(MP2)] Study

• Published in: Journal of organic chemistry Vol. 63; no. 24; pp. 8995 - 8997
• Main Authors: Abboud, J.-L. M, Castaño, O, Herreros, M, Leito, I, Notario, R, Sak, K
• Format: Journal Article
• Language: English
• Published: American Chemical Society 27.11.1998
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo981369y

The standard Gibbs energy change for the halide transfer between tert-butyl chloride and trichlorocyclopropenyl cation has been determined by means of Fourier transform ion cyclotron resonance mass spectrometry. Trichlorocyclopropenyl cation is found to be substantially more stable than tert-butyl and 1-adamantyl cations. This reaction and cognate processes were also studied at the ab initio G2(MP2) level. The agreement between experimental and calculated changes of thermodynamic state functions is remarkably good. On the basis of these results, isodesmic and homodesmotic reactions were constructed. They led to the delocalization energy in 1 and to the quantitative assessment of substituent effects on the stability of the aromatic 2π-electron system.