11. The dirhodium ( II ) tetracarboxylate metallocarbene stabilized by ?C-Rh?! ?C = O hyperconjugation . 12. It has been shown, however, that hyperconjugation does depend on the solvent in the system. 13. His work was a crucial first step to the beginnings of the ideas of hyperconjugation and conjugation effects. 14. Of these two models, hyperconjugation is generally considered the principal cause behind the gauche effect in difluoroethane. 15. One alternative to the steric hindrance explanation is based on hyperconjugation as analyzed within the Natural Bond Orbital framework. 16. To quantify hyperconjugation effect, they designed the following isodesmic reactions in 1-butyne and 1-butene. 17. Gronert claims that his model successfully reproduces accepted data without invoking hyperconjugation and can perhaps explain well-established trends. 18. An instance where hyperconjugation may be overlooked as a possible chemical explanation is in rationalizing the rotational barrier of ethane. 19. The lowering of the LUMO is the result of hyperconjugation between alkyne ? donor orbitals and CF ? * acceptors. 20. Some authors also question the validity of this hyperconjugation model based on results from the quantum theory of atoms in molecules.
