Capture of Cesium Ions with Nanoclusters: Effects on Inter- and Intramolecular Assembly

The capture of cations with nanoclusters is a flourishing area in the nanocluster science due to their effects on both molecular chemistry and supramolecular chemistry. The capture of Cs+ is most concerned in this field for its capability of controlling the synthesis and assembly of nanoclusters. However, the atomically precise interaction between Cs+ ions and nanoclusters remains mysterious. In this paper, we report the first X-ray crystal structure of a Cs+-captured nanocluster, formulated as Cs3Ag29(SSR)(12)(DMF)(x) (x = 5, 6; SSR, 1,3-benzene dithiol). The capture of Cs+ with Ag-29(SSR)(12)(PPh3)(4) peels the PPh3 ligands off from the nanocluster surface, giving rise to Cs3Ag29(SSR)(12)(DMF)(x). The Cs+-cluster interactions not only alter the geometric structure of the Ag-29(SSR)(12) kernel but also assemble Ag-29(SSR)(12) clusters into one-dimensional, cluster-based lines. Remarkable differences have been observed by comparing the optical properties of the Cs3Ag29(SSR)(12)(DMF)(x) nanocluster in solutions or in crystallized films. Overall, this work is of great significance for revealing both the Cs+-induced intracluster transformation of nanocluster structures and the Cs+-induced intercluster self-assembly.