Organic-Inorganic High-Valence Sn18-oxo Clusters: Direct Utilization of an Inorganic Sn(IV) Source to Improve the Nuclearity and Electrocatalytic CO2 Reduction Properties

The high-valence tin-oxo clusters are of great significance because of their structural diversity and potentialapplications in manyfields, e.g., catalysis, extreme ultraviolet (EUV)lithography, and so on. The synthesis of high-nuclearity tin-oxoclusters remains a great challenge currently, since the key inorganicSnxOycore with Sn(4+)ions could not be obtained only by the in situSn-C bond cleavage in organic tin sources. In this context, wesynthesize three organic-inorganic hybrid Sn-18-oxo clusters,[(BuSn)(12)Sn-6(mu(3)-O)(20)(ba)(12)(PhPO3)(4)] (Bu = butyl, Hba = benzoicacid), [(BuSn)(12)Sn-6(mu(3)-O)(20)(pmba)(12)(PhPO3)(4)]center dot 2CH(3)CN center dot 2H(2)O(Hpmba =p-toluic acid), and [(BuSn)12Sn6(mu 3-O)(20)(ptba)(12)(PhPO3)(4)]center dot 2CH(3)CN center dot 2iPrOH center dot 2H(2)O (Hptba =p-tert-butyl benzoic acid), as well as one Sn-6-oxo cluster [(BuSn)(6)(mu(3)-O)(2)(mu(2)-OH)(4)(pnba)(6)(PhPO3)(2)] (Sn-6) (Hpnba =p-nitrobenzoic acid) by combining an inorganic precursor (SnCl4) with an organicone (butyltin hydroxide oxide). It is shown that an inorganic dicyclo-chain-like Sn6O8 core encapsulated in a U-shapeddodecanuclear butyltin-oxo ring plays an important role in the construction of Sn-18-oxo clusters and that the use of a ligand with anelectron-withdrawing group reduces the nuclearity of clusters to Sn6. Moreover, electrocatalytic CO2 reduction studies confirm thatthe electrocatalytic activities of the Sn-18 clusters are superior to those of the Sn6cluster, probably due to the hybrid organotin-inorganotin structures. Our work not only opens a new way for constructing high-nuclearity tin-oxo clusters but also is helpful indeeply revealing the structure-properties relationship of tin-oxo clusters

Automated summary

High-valence tin-oxo clusters have structural diversity and potential applications. The synthesis of these clusters is challenging, but this study successfully synthesized various organic-inorganic hybrid tin-oxo clusters and explored the relationship between structure and properties.