[MoO ₄] ²⁻-templated D _{4 h} -symmetric sandwich Ag ₁₃ nanocluster coprotected with thiolate and phosphine

Mixed-ligand and anion-templated strategies in constructing metal nanoclusters are intricate and ingenious processes that face challenges to be studied. Herein, we report a cationic [Ag13(MoO4)4(SC6H4iPr)2(dppp)8]3+ (Ag13) nanocluster, which is templated using four [MoO4]2− anions and coprotected by 4-isopropylphenol (iPrC6H4S−) and 1,3-bis (diphenylphosphino) propane (dppp). Two capped (Ag4SC6H4iPr)2 units connect with the middle Ag@Ag4 layer via four [MoO4]2− anion templates to form a three-layer D4h-symmetric structure. An ideal crystallographic fourfold axis passes through the central Ag atom and the S and C atoms of the iPrC6H4S− ligand. The layer stacking generates a nonface-centered cubic (nonFCC) structure. The structure and composition of the Ag13 nanocluster have been fully characterized. In addition, the solid ultraviolet–visible (UV–vis) spectra show that Ag13 is a potential narrow-band-gap semiconductor. The photoluminescence (PL) of orange-yellow-light emission is attributed to ligand-to-metal charge transfer. This work has advanced the research on shell engineering of anionic templates and coprotection to assemble high-symmetric Ag nanoclusters.