Spontaneous formation of autocatalytic sets with self-replicating inorganic metal oxide clusters.

Here we show how a simple inorganic salt can spontaneously form autocatalytic sets of replicating inorganic molecules that work via molecular recognition based on the {PMo} ≡ [PMoO] Keggin ion, and {Mo} ≡ [HMoM(NO)O(HO)] cluster. These small clusters are able to catalyze their own formation via an autocatalytic network, which subsequently template the assembly of gigantic molybdenum-blue wheel {Mo} ≡ [MoOH(HO)], {Mo} ≡ [MoMoO(CHCOO)(HO)] ball-shaped species containing 154 and 132 molybdenum atoms, and a {PMo}⊂{MoCe} ≡ [HMoMoCeO(HO) (PMoMoO)(CHNOS)] nanostructure. Kinetic investigations revealed key traits of autocatalytic systems including molecular recognition and kinetic saturation. A stochastic model confirms the presence of an autocatalytic network involving molecular recognition and assembly processes, where the larger clusters are the only products stabilized by the cycle, isolated due to a critical transition in the network.