Cycle (1) involves multiple ethylene dimerization products (Fig. ). One catalytic cycle simply closes through an ethylene insertion (denoted as type I) and a β-hydride transfer (denoted as type II). Following further type I-II steps occurring on Ga-ethyl with an adsorbed 1-butene (species 5 ), cis-2-butene and isobutene can also form (Fig. ). To complete the catalytic cycle of cycle (2), one propylene molecule can be obtained through C-C bond breaking of a Ga-2-butyl species (reverse type I). The production of a second propylene molecule occurs via the same Cossee-Arlman oligomerization cycle initiated by the Ga-methyl intermediate (species 9 , Fig. ). In cycle (3), the type III elementary step generates an alkane, which may occur for all Ga-alkyl intermediates, and an alkyne, like acetylene, is formed that balances the stoichiometry. C n H 2n species, and C n H 2n-2 isomers. The combination of these three elementary catalytic cycles thus results in a broad diversity of possible products.