The Oxidative Mechanism in Electrophilic CH Activation: The Case of CH2F2 and CH2Cl2

The H.‐atom transfer (HAT) reaction is investigated in the gas phase, starting from two different entrance channels, O2.+/CH2X2 and CH2X2.+/O2 (X=F, Cl), that correspond to a step of hydride transfer and to HAT, respectively. Analysis of the spin and charge along the reaction pathway shows that HAT occurs through the same reacting configuration, irrespective of whether the reactants are formed within the complex or are free isolated species. Something to hang your HAT on: CH activation by H− and H. transfer proceed through similar saddle points, starting from different entrance channels. The blue and red lines represent the spin‐density change on CH2F2 and CH2Cl2.+ whilst transferring H− to O2.+ and H. to O2, respectively. The saddle points show the spin density that is delocalized on the oxygen moiety and on the halomethane CH group.