A theoretical study of the activation of methane by gold(III) homoleptic complexes

The density functional theory method with the PBE functional, SBK pseudopotential, and extended basis sets was used to study the reaction between methane and gold(III) homoleptic complexes, namely, [AuX4](-) (X = Cl, Br, I, H, CN, NH2, OH, CH3, and SH), [Au (X(CY)(2)X)(2)](-) (X = S, Y = H; X = Y = O), Au2Cl6, [Au(X-2(CY))(2)](+) (X = S, Y = NH2; X = O, Y = H), and [Au(acac)(2)](+), with the formation of electrophilic substitution products. The activation of methane under mild conditions was found to be uncharacteristic of anionic and neutral complexes. According to calculations of cationic oxygen-containing complexes, the formation of methane complexes is possible in their reactions with methane. The energy barrier to this reaction noticeably decreases because of the activation of the C - H bond in this complex. The heat effects vary widely depending on the nature of the ligand. There is, however, no obvious correlation between their values and the activation energy of the reaction.