Ab initio calculations have been performed for the H-atom abstraction reactions from a series of halogenated methanes by the hydroxyl radical. Geometry optimization and vibrational frequency calculations were performed for reactants, transition states and products at the MP2/6-311G(2d,2p) level of theory. Single-point energy calculations were carried out at the PMP2/6-311G(3df,2p) and PMP4/6-311++G(3df,3pd) levels. Canonical transition state theory was used to predict the rate constants as function of the temperature (250 K to 400 K) taking into account the tunneling correction. Atmospheric lifetimes and infrared radiative forcings of halomethanes were estimated based on results of these ab initio calculations.
Citation: Journal of Physical Chemistry A
Issue: No. 38
Pub Type: Journals
ab initio, atmospheric lifetime, halomethanes, hydroxyl radical, radiative forcing