Comparative analysis of blue‐shifted hydrogen bond versus conventional hydrogen bond in methyl radical complexes |
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| Authors: | Kai Tang Fu Qiang Shi |
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| Institution: | 1. Key Laboratory of Fire Fighting and Rescuing Technology, Chinese People's Armed Police Forces Academy, Langfang, Hebei Province 065000, People's Republic of ChinaKey Laboratory of Fire Fighting and Rescuing Technology, Chinese People's Armed Police Forces Academy, Langfang, Hebei Province 065000, People's Republic of China;2. College of Chemistry, Peking University, Beijing 100871, People's Republic of China |
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| Abstract: | Methyl radical complexes H3C…HCN and H3C…HNC have been investigated at the UMP2(full)/aug‐cc‐pVTZ level to elucidate the nature of hydrogen bonds. To better understand the intermolecular H‐bond interactions, topological analysis of electron density at bond critical points (BCP) is executed using Bader's atoms‐in‐molecules (AIM) theory. Natural bond orbital (NBO) analysis has also been performed to study the orbital interactions and change of hybridization. Theoretical calculations show that there is no essential difference between the blue‐shift H‐bond and the conventional one. In H3C…HNC complex, rehybridization is responsible for shortening of the N? H bond. The hyperconjugative interaction between the single electron of the methyl radical and N? H antibonding orbital is up to 7.0 kcal/mol, exceeding 3.0 kcal/mol, the upper limit of hyperconjugative n(Y)→σ*(X–H) interaction to form the blue‐shifted H‐bond according to Alabugin's theory. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 |
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| Keywords: | hydrogen bond aug‐cc‐pVTZ bond critical point NBO analysis radical |
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