Computational study of bonding trends in the metalloactinyl series EThM and MThM′ (E = N−, O, F+; M, M′ = Ir−, Pt, Au+)

The title systems, including EThE′, are treated at DFT level using a B3LYP functional and small-core quasirelativistic pseudopotentials. Most of the studied systems are bent, like their isoelectronic ThO2 analogue, except for some anionic systems containing Ir. The bond lengths vary considerably and can lie above or below the sum of triple-bond covalent radii. Among the studied systems, the iridium-containing species show the strongest back-donation to Th. The bonding can be simply understood and could theoretically go up to a ‘24-electron principle’ limit at the actinide.