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Updated: Feb 28, 2026
Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Isotope-Controlled Selectivity by Quantum Tunneling: Hydrogen Migration versus Ring Expansion in
Ashim Nandi1, Dennis Gerbig2, Peter R Schreiner2
1Department of Chemistry, Ben-Gurion University of the Negev , Beer-Sheva 841051, Israel.
Abstract:
Using the tunneling-controlled reactivity of cyclopropylmethylcarbene, we demonstrate the viability of isotope-controlled selectivity (ICS), a novel control element of chemical reactivity where a molecular system with two conceivable products of tunneling exclusively produces one or the other, depending only on isotopic composition. Our multidimensional small-curvature tunneling (SCT) computations indicate that, under cryogenic conditions, 1-methoxycyclopropylmethylcarbene shows rapid H-migration to 1-methoxy-1-vinylcyclopropane, whereas deuterium-substituted 1-methoxycyclopropyl-d3-methylcarbene undergoes ring expansion to 1-d3-methylcyclobutene. This predicted change in reactivity constitutes the first example of a kinetic isotope effect that discriminates between the formation of two products.
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