Assembly of high-nuclearity Sn26, Sn34-oxo clusters: solvent strategies and inorganic Sn incorporation

Abstract

A series of unprecedented high-nuclearity tin-oxo nanoclusters (up to Sn₃₄) with structural diversity have been obtained. The characteristics of the applied solvents had great influence on the assembly of these Sn–O clusters. Pure alcohol environments only gave rise to small clusters of Sn₆, whilst the introduction of water significantly increased the nuclearity to Sn₂₆, which greatly exceeds those of the known tin-oxo clusters (≤14); the use of aprotic CH₃CN finally produced the largest Sn₃₄ to date. Apart from the nuclearity breakthrough, the obtained tin-oxo clusters also present new structural types that are not found in previous reports, including a layered nanorod-like structure of Sn₂₆ and the cage-dimer structure of Sn₃₄. The layered Sn₂₆ clusters represent good molecular models for SnO₂ materials. Moreover, an electrode derived from TOC-17 with a {Sn₂₆} core shows better electrocatalytic CO₂ reduction activity than that from TOC-18 with Sn₃₄. This work not only provides an efficient methodology for the rational assembly of high-nuclearity Sn–O clusters, but also extends their potential applications in energy conversion.