D.J.O. thanks Pomona College for supporting this research. M.P.M. acknowledges NIGMS (GM87706-01).
On the Origin of Conformational Kinetic Isotope Effects†
Article first published online: 17 FEB 2011
Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Angewandte Chemie International Edition
Volume 50, Issue 11, pages 2564–2567, March 7, 2011
How to Cite
O'Leary, D. J., Rablen, P. R. and Meyer, M. P. (2011), On the Origin of Conformational Kinetic Isotope Effects. Angew. Chem. Int. Ed., 50: 2564–2567. doi: 10.1002/anie.201007322
- Issue published online: 2 MAR 2011
- Article first published online: 17 FEB 2011
- Manuscript Received: 22 NOV 2010
- NIGMS. Grant Number: GM87706-01
- ab initio calculations;
- conformation analysis;
- isotope effects
Neatly dissected: The computed conformational kinetic isotope effects (KIEs) for biphenyls 1 and 2 (X=D or H) are in good agreement with experimental values and have been partitioned according to the Bigeleisen–Mayer and ΔH/ΔS approaches. In [D8]-1 the KIE is dominated by a normal entropic contribution which overshadows an enthalpic contribution determined by Hvib and not HZPE. The inverse isotope effect in [D6]-2 is governed by an enthalpic zero-point energy term (HZPE) working against a normal entropic contribution.