Push-pull allenes-conjugation, (anti)aromaticity and quantification of the push-pull character
- Structures, H-1/C-13 chemical shifts, and pi electron distribution/conjugation of an experimentally available and theoretically completed set of push-pull allenes Acc(2)C=C=CDon(2) (Acc=F, CHO, CF3, C N; Don=t-Bu, OMe, OEt, SMe, SEt, NCH2R) have been computed at the OFT level of theory. Both orthogonal linear and orthogonal bent structures have been obtained. In the latter case the push-pull character could be quantified by the quotient method. The C-13 chemical shift of the central allene carbon atom C-2 and chemical shift differences Delta delta(C-1, C-2) and Delta delta(C-2, C-3) of allene carbon atoms proved to be a quantitative alternative. TSNMRS of ring-closed push-pull allenes have been computed in addition and were employed to identify polar, carbene-like and carbone-like canonical structures of these molecules.
Author details: | Erich KleinpeterORCiDGND, Peter Werner, Andreas KochORCiDGND |
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DOI: | https://doi.org/10.1016/j.tet.2013.01.027 |
ISSN: | 0040-4020 |
Title of parent work (English): | Tetrahedron |
Publisher: | Elsevier |
Place of publishing: | Oxford |
Publication type: | Article |
Language: | English |
Year of first publication: | 2013 |
Publication year: | 2013 |
Release date: | 2017/03/26 |
Tag: | Aromaticity; C-13 NMR spectroscopy; ICSS; Push-pull allenes; Push-pull character; Quotient method; TSNMRS |
Volume: | 69 |
Issue: | 11 |
Number of pages: | 10 |
First page: | 2436 |
Last Page: | 2445 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
Peer review: | Referiert |