Controlled Shell and Kernel Modifications of Atomically Precise Pd/Ag Superatomic Nanoclusters

Abstract

AbstractThe first 8‐electron Pd/Ag superatomic alloys with an interstitial hydride [PdHAg19(dtp)12] (dtp=S2P(OiPr)2−) 1 and [PdHAg20(dtp)12]+ 2 are reported. The targeted addition of a single Ag atom to 1 is achieved by the reaction of one equivalent of trifluoroacetic acid, resulting in the formation of 2 in 55 % yield. Further modification of the shell results in the formation of [PdAg21(dtp)12]+ 3 via an internal redox reaction, with the system retaining an 8‐electron superatomic configuration. The interstitial hydride in 1 and 2 contributes its 1s1 electron to the superatomic electron count and occupies a PdAg3 tetrahedron. The distributions of isomers corresponding to different dispositions of the outer capping Ag atoms are investigated by multinuclear VT NMR spectroscopy. The emissive state of 3 has a lifetime of 200 μs (λex=448; λem=842), while 1 and 2 are non‐emissive. The catalytic reduction of 4‐nitrophenol is demonstrated with 1–3 at room temperature.