Journal of the American Chemical Society

Hyperconjugation: equilibrium secondary isotope effect on the stability of the tert-butyl cation. Kinetics of near-thermoneutral hydride transfer

M Meot-Ner

Index: Meot-Ner, Michael (Mautner) Journal of the American Chemical Society, 1987 , vol. 109, # 26 p. 7947 - 7950

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Citation Number: 7

Abstract

Abstract: The thermochemistry of the hydride transfer equilibrium (CD3) 3C++(CH3) $ H+(CH3) $++(CD&CH was measured by pulsed high-pressure mass spectrometry. Measurements over a wide temperature range, 145-600 K, allowed an accurate determination of the values: AHo=-0.57 f 0.02 kcal/mol; ASo=-0.57 f 0.08 cal/(mol. K);=-0.40 f 0.07 kcal. mol; and K298= 1.97 f 0.20. The direction of the observed isotope effect is ...