CHF2CF2OCHF2: conformational analysis and direct dynamics study of its reaction with Cl atoms and atmospheric fate

Abstract

Ten distinct conformers of a CHF₂CF₂OCHF₂ molecule are identified from the exploration of the conformational space and the potential energy profile of the same is constructed from quantum chemical calculations at the M06-2X/6-311++G(d,p) level. Kinetics, mechanism and thermochemistry of the reaction of the two lowest energy conformers of the CHF₂CF₂OCHF₂ molecule with Cl atoms are investigated at the same level of theory. The rate coefficient for the H-abstraction reaction is calculated for the first time using the canonical variational transition state theory (CVT) along with small curvature tunneling (SCT) correction over the temperature range of 200–1000 K and fitted into a three-parameter Arrhenius equation. The subsequent atmospheric degradation of the product radical C˙F₂CF₂OCHF₂ is explored to understand its possible fate and impact in the atmosphere.