## Abstract

Ab initio investigations at the MP2 and CCSD(T) level with augmented double and triple zeta basis sets have identified various stationary points on the B^{+}/nCH_{4}, n= 1, 2 hypersurfaces. The electrostatic complexes show a strong variation in the sequential binding energy with D_{e} for the loss of one CH_{4} moleucle calculated to be 16.5 and 6.8kcal mol^{−1} for the n = 1 and n = 2 complexes, respectively. The covalent molecular ion, CH_{3}BH^{+}, is found to have the expected C_{3v} geometry and to be strongly bound by 84.0 kcal mol^{−1} with respect to B^{+}+ CH_{4}. The interaction of CH_{4} with CH_{3}BH^{+} is qualitatively very similar to the interaction of CH_{4} with HBH^{+}, however, the binding is only about 50% as strong due to the electron donating characteristic of the methyl group. of particular interest are the insertion transition states which adopt geometries allowing the B^{+} ion to interact with multiple sigma bonds. In the n = 1 case, the interaction with two CH bonds lowers the insertion activation energy by about 25 kcal mol^{−1} from that expected for a mechanism involving only one sigma bond. For n = 2, B^{+} interactswith two CH sigma bonds from one CH_{4} and one CH sigma bond from the other CH_{4} leading to an additional activation energy decrease of about 15.7 kcal mol^{−1} relative to B^{+}+nCH_{4}.

Original language | English |
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Pages (from-to) | 477-485 |

Number of pages | 9 |

Journal | Faraday Discussions |

Volume | 118 |

Issue number | 1 |

DOIs | |

State | Published - 2002 |