A combined DFT-predictive and experimental exploration of the sensitivity towards nucleofuge variation in zwitterionic intermediates relating to mechanistic models for unimolecular chemical generation and trapping of free C2 and alternative bimolecular pathways involving no free C2.
| Title: | A combined DFT-predictive and experimental exploration of the sensitivity towards nucleofuge variation in zwitterionic intermediates relating to mechanistic models for unimolecular chemical generation and trapping of free C2 and alternative bimolecular pathways involving no free C2. |
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| Authors: | Rzepa HS; Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, Wood Lane, London W12 OBZ, UK. rzepa@imperial.ac.uk.; Arita M; Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. kmiya@mol.f.u-tokyo.ac.jp.; Miyamoto K; Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. kmiya@mol.f.u-tokyo.ac.jp.; Uchiyama M; Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. kmiya@mol.f.u-tokyo.ac.jp.; Research Initiative for Supra-Materials (RISM), Shinshu University, 3-15-1 Tokita, Ueda, 386-8567, Japan. |
| Source: | Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2022 Nov 02; Vol. 24 (42), pp. 25816-25821. Date of Electronic Publication: 2022 Nov 02. |
| Publication Type: | Journal Article |
| Language: | English |
| Journal Info: | Publisher: Royal Society of Chemistry Country of Publication: England NLM ID: 100888160 Publication Model: Electronic Cited Medium: Internet ISSN: 1463-9084 (Electronic) Linking ISSN: 14639076 NLM ISO Abbreviation: Phys Chem Chem Phys Subsets: MEDLINE; PubMed not MEDLINE |
| Imprint Name(s): | Original Publication: Cambridge [England] : Royal Society of Chemistry, c1999- |
| Abstract: | Following the recent report of the chemical generation and trapping at room temperatures of C2, generated from an alkynyl phenyl iodonium salt, a computational analysis had indicated that both unimolecular fragmentation and bimolecular substitution mechanisms for the process could be envisaged. Here a combined theoretical and experimental analysis explores how the energetics of these mechanisms and resulting experimental products respond to variation in the nucleofuge. When the phenyl iodonium nucleofuge is replaced by pyridinium, trapping products are again obtained, which we conclude favours a bimolecular mechanism involving no free C2. Trapped products in greater yield were also observed using dibenzothiophenium as the nucleofuge in both condensed solution phase and most significantly in a two-flask room temperature experiment in which a volatile species, presumed to be C2, is transferred and trapped in a second flask. The energetics of the unimolecular fragmentation process producing C2 are predicted to be too high to correspond to a facile thermal reaction, which means that an experimental/theoretical dichotomy remains to be explained. |
| Entry Date(s): | Date Created: 20221024 Date Completed: 20221103 Latest Revision: 20221103 |
| Update Code: | 20260130 |
| DOI: | 10.1039/d2cp01214f |
| PMID: | 36278412 |
| Database: | MEDLINE |
Journal Article