Gold complexes with oxygen-containing ligands as a catalyst for methane oxidation

The reactions of methane with the gold complexes [Au(OH)](-), [Au(OCH3)(4)](-), [Au(O(CO)(2)O)(2)](-) and [Au(O2CH)(2)](+), [Au-I(acac)], [Au-III(acac)(2)](+) (acac - acetylacetonato) were studied using the DFT/PBE method with the SBK basis set. High activation barriers were obtained for the electrophilic substitution in [Au(OH)](-), [Au(OCH3)(4)](-), [Au(O(CO)(2)O)(2)](-) and [Au-III(acac)(2)](+) complexes, which excludes the possibility that these reactions might proceed under mild conditions. The reactions of the [Au(HCO2)(2)](+) and [Au-I(acac)] complexes with methane have rather low energy barriers and proceed through the formation of an intermediate complex. The alternative mechanism of methane oxidation with a gold complex in the presence of oxygen is simulated.