Possible contribution of tunneling to the high secondary a-deuterium kinetic isotope effect

Possible contribution of tunneling to the high secondary a-deuterium kinetic isotope effect 

As already pointed out, the acetolysis and formolysis of dideuterioferro-cenylmethyl benzoate exhibit large secondary a-D KIEs, and an abnormal temperature dependence has also been observed. In the presence of LiC104 ca. 0.1 moldm ), which prevents reversion from solvent-separated to contact ion pairs, 25 °C amounted to 1.53 0.02 (acetolysis) and 1.48  

Values below unity have also been found for secondary deuterium isotope effects and have been given a similar explanation.  

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