A theoretical study of hydrogen and chlorine transfer reactions from fluorine- and chlorine-substituted methanes by F3C˙ radicalsElectronic supplementary information (ESI) available: Vibrational frequencies, partition functions, hindered rotational barriers, imaginary frequencies, electronic charge distributions, polarity variation and reaction enthalpies for reactants, transition structures and products. See http://www.rsc.org/suppdata/cp/b1/b110897b/