Quantification of the push-pull effect in substituted alkynes : evaluation of +/- I/+/- M substituent effects in terms of C C bond length variation
- C-13 chemical shifts of alkynes, published to date, were computed at the DFT (B3LYP/6-311G*) level of theory and compared with the experimental delta values, and the agreement was employed as a measure of quality for the underlying structures. For the corresponding global minima structures, thus obtained, the occupation quotients of antibonding pi* and bonding pi orbitals (pi*(C C)/pi(C C)) and the bond lengths (d(C C)) of the central C C triple bond were computed and correlated to each other. The linear dependence obtained for the two push-pull parameters d(C C) and pi*(C C)/pi(C C) quantifies changes in the push-pull effect of substituents while deviations from the best line of fit indicate and ascertain quantitatively to what extend the inductive (+/-l) substituent effect changes with respect to the bond length of the C C triple bond.
Author details: | Erich KleinpeterORCiDGND, Andrea Frank |
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URL: | http://pubs.acs.org/journal/jpcafh |
DOI: | https://doi.org/10.1021/Jp9024359 |
ISSN: | 1089-5639 |
Publication type: | Article |
Language: | English |
Year of first publication: | 2009 |
Publication year: | 2009 |
Release date: | 2017/03/25 |
Source: | Journal of physical chemistry / A. - ISSN 1089-5639. - e-ISSN 1520-5215. - 113 (2009), 24, S. 6774 - 6778 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
Peer review: | Referiert |