Multiple 3c2e bonding of methane with metal cations

Methane is a greenhouse gas but at the same time a possible starting material in chemical industry. Here, we demonstrate by computational methods that methane could form in gas phase stable adducts with alkaline and earth alkaline metal cations. The interaction can be described as multiple 3c2e bonding between a cation and CH bonds. In the alkaline metal adducts the open mode prevails, while for the earth alkaline moieties it is difficult to define, whether there is either close or open mode prevailing.