Abstract
CNDO/2 calculations together with a partitioning of the energy into various one- and two-centre components have been performed on CH3CN, CH3NC, and a large number of nuclear configurations formed by placing the methyl group at various positions with respect to the fixed CN group. A complete potential energy surface was obtained showing that a minimum in energy occurred for a pyramidal CH3 group placed at approximately 90° to the CN axis. The barrier to the reaction CH3NC→CH3CN is calculated as 32.9 kcal, in reasonable agreement with 38.4 kcal, the experimental value of Rabinovitch. A charge separation equivalent to [CH +0.223 ][CN−0.22] is found for the intermediate compared to [CH +0.083 ][CN−0.08] and [CH +0.123 ][NC−0.22] for the cyanide and isocyanide, respectively.
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Moffat, J.B., Tang, K.F. The methyl isocyanide isomerization: A CNDO/2 study with partitioning of energy. Theoret. Chim. Acta 32, 171–182 (1973). https://doi.org/10.1007/BF00528489
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DOI: https://doi.org/10.1007/BF00528489