TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Schulenburg, Anja
T1  - Quantification of the push-pull effect in tolanes and a revaluation of the factors affecting the C-13 chemical shifts of the carbon atoms of the C=C triple bond
N2  - Variously substituted tolanes were employed to show that the push-pull effect is also active in C equivalent to C triple bonds by the successful correlation of the occupation quotient pi*/pi of the pi orbital in resonance with the substituted phenyl moieties of tolanes versus the bond length of the C equivalent to C triple bond. In addition, the influences of the ortho phenyl ring substituents on the C-13 chemical shifts of the triple bond carbon atoms, which were estimated by Rubin et al.(4) to be "inapplicable for describing triple bond polarization", were re-evaluated, leading to the conclusion that, while anisotropic effects of ortho substituents are negligible, the steric ortho-substituent effects do in fact dominate the deviations obtained. A detailed theoretical NBO/NCS study has been employed to illuminate the facts of this case
Y1  - 2006
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/11979
UR  - http://pubs.acs.org/journal/joceah
SN  - 0022-3263
ER  -