Deuterium isotope effects on carbon-13 chemical shifts in cyclophanes. Deshielding intrinsic through-space and through-bond effects

L Ernst, S Eltamany, H Hopf

Index: Ernst,L.; Eltamany,S.; Hopf,H. Journal of the American Chemical Society, 1982 , vol. 104, p. 299

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Citation Number: 28

Abstract

For two da orbitals to be orthogonal, they must be at 54.7'(or 125.3'), as in Figure la. However, intraatomic electron repulsion destabilizes this optimum da dd configuration18 and favors a dn d6 configuration that would lead to a 90'bond angle. The observed optimum angle of-75'is a compromise between these two effects.