Distinction of Push,pull effect and steric hindrance in disubstituted alkynes
- The push,pull effect in two series of disubstituted alkynes was studied at the DFT level [B3LYP/6-311G(d)] by application of the 13C chemical shift differences (GIAO) between the alkyne carbon atoms (Delta delta (C C)), the charge difference between these carbons (Delta q(C C)), the occupation quotient (NBO) of anti-bonding pi*, and bonding pi orbitals (pi*(C C)/pi(C C)) and the bond length (d(C C)) of the C C triple bond. The linear dependence of d(C C) versus pi*(C C)/pi(C C) quantifies changes in the push,pull effect while deviations from the latter correlation indicate and ascertain quantitatively to what extent steric hindrance restricts the strain-less conjugation of the C C triple bond pi- orbitals in the disubstituted alkynes.
| Author details: | Erich KleinpeterORCiDGND, Andrea Frank |
|---|---|
| URL: | http://www.sciencedirect.com/science/journal/00404020 |
| DOI: | https://doi.org/10.1016/j.tet.2009.03.075 |
| ISSN: | 0040-4020 |
| Publication type: | Article |
| Language: | English |
| Year of first publication: | 2009 |
| Publication year: | 2009 |
| Release date: | 2017/03/25 |
| Source: | Tetrahedron. - ISSN 0040-4020. - 65 (2009), 22, S. 4418 - 4421 |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
| Peer review: | Referiert |
