Embryonic Growth of Face-Center-Cubic Silver Nanoclusters Shaped in Nearly Perfect Half-Cubes and Cubes

Demonstrated
herein are the preparation and crystallographic characterization
of the family of fcc silver nanoclusters from Nichol’s cube
to Rubik’s cube and beyond via ligand-control (thiolates and
phosphines in this case). The basic building block is our previously
reported fcc cluster [Ag14(SPhF2)12(PPh3)8] (1). The metal frameworks
of [Ag38(SPhF2)26(PR′3)8] (22) and
[Ag63(SPhF2)36(PR′3)8]+ (23), where HSPhF2 = 3,4-difluorothiophenol and R′
= alkyl/aryl, are composed of 2 × 2 = 4 and 2 × 2 ×
2 = 8 metal cubes of 1, respectively. All serial clusters
share similar surface structural features. The thiolate ligands cap
the six faces and the 12 edges of the cube (or half cube) while the
phosphine ligands are terminally bonded to its eight corners. On the
basis of the analysis of the crystal structures of 1, 22, and 23, we predict the next “cube of cubes” to be Ag172(SR)72(PR′3)8] (33), in the evolution of growth of
this cluster sequence.