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

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 117; no. 20; pp. 10699 - 10705
• Main Authors: Miras, Haralampos N., Mathis, Cole, Xuan, Weimin, Long, De-Liang, Pow, Robert, Cronin, Leroy
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 19.05.2020
• Subjects: Assembly; Clusters; Inorganic salts; Metal oxides; Molybdenum; Physical Sciences; Recognition; Replicating; Stochastic models; Stochasticity; self-assembly; autocatalytic sets; origin of life; autocatalysis; molecular replication
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1921536117

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 {PMo12} ≡ [PMo12O40]3– Keggin ion, and {Mo36} ≡ [H₃Mo57M₆(NO)₆O183(H₂O)18]22– 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 {Mo154} ≡ [Mo154O462H14(H₂O)70]14–, {Mo132} ≡ [MoVI 72MoV 60O372(CH₃COO)30(H₂O)72]42– ball-shaped species containing 154 and 132 molybdenum atoms, and a {PMo12}⊂{Mo124Ce₄} ≡ [H16MoVI 100MoV 24Ce₄O376(H₂O)56 (PMoVI 10MoV₂O40)(C₆H12N₂O₄S₂)₄]5– 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.