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

The 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 1s(1) 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 mu s (lambda(ex)= 448; lambda(em)= 842), while 1 and 2 are non-emissive. The catalytic reduction of 4-nitrophenol is demonstrated with 1-3 at room temperature.

Automated summary

The first 8-electron Pd/Ag superatomic alloys with an interstitial hydride [PdHAg19(dtp)(12)] and [PdHAg20(dtp)(12)](+) are reported. Addition of a single Ag atom to [PdHAg19(dtp)(12)] through the reaction of trifluoroacetic acid yields [PdHAg20(dtp)(12)](+) in 55% yield. Further modification of the shell results in the formation of [PdAg21(dtp)(12)](+) via an internal redox reaction. The interstitial hydride in [PdHAg19(dtp)(12)] and [PdHAg20(dtp)(12)](+) contributes its 1s(1) electron and occupies a PdAg3 tetrahedron.