Chlorine KIE

Fig. 11.12 ONIOM model used in calculations of the chlorine KIE on DhlA catalyzed reaction (Lewandowicz, A., Matsson, O., Paneth, P., et al. J. Am. Chem. Soc. 123, 4550 (2001))...

Fig. 1 The dependence of the chlorine KIE on the Wiberg Ca-Cl transition state bond order for the Sn2 reactions of methyl chloride with 26 different nucleophiles. The dashed line is the KIE estimated using the BEBOYIB approach. Reprinted with permission from Ref. [11]. Copyright (2004) American Chemical Society.

The temperature-independent term or imaginary frequency contribution to the chlorine KIE. 

It is worth noting that adding water as the solvent with the PCM continuum solvent model16 and the conductor field model of electrostatic interactions (COSMO)17 or even specific water molecules to the calculations did not alter the chlorine KIEs, nor the conclusion, significantly. Also noteworthy is the observation that neither the method of calculating the transition state bond order nor anharmonicity affected the conclusions. 

Measured in DMSO. Changing the solvent does not alter the chlorine KIE in these reactions. 4The nucleophile was sodium para-methoxyphenoxide. 

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