H/D kinetic isotope effect in HCOOH cis–trans conversion of formic acid in noble gas matrices

Intramolecular tunneling of hydrogen and deuterium atoms in noble gas matrices (Ar, Kr and Xe) has been studied theoretically for cis–trans isomerization of formic acid at low temperatures. The temperature dependence of the tunneling rate constant and quantum kinetic isotope effect taking into account the media reorganization upon the H/D atomic transfer is described in terms of the modified theory of radiationless transitions. The theoretical results are found to be in a reasonable agreement with the literature experimental data on the rate constants and the anomalous quantum kinetic H/D isotope effect.