[MoO₄]²⁻-templated D_4h-symmetric sandwich Ag₁₃ 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 D_4h-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.