Programmable Synthesis of Silver Wheels

The synthesis of sandwich-shaped multinuclear silver complexes with planar penta- and tetranuclear wheel-shaped silver units and a central anion, [Ag-n(2-HPB)(2)(A(-))](OTf-)(n-1), nAg(A), n = 4 or 5 and A(-) = OH- or F- or Cl-, is reported, along with complete spectroscopic and structural characterization. An NMR mechanistic study reveals that silver complexes were formed in the following order: 2Ag -> 3Ag(H2O) -> 5Ag(OH) -> 4Ag(OH). The central hydroxides in 4Ag(OH) and 5Ag(OH) exhibit exotic physical properties due to the confined environment inside the complex. The size of these silver wheels can be tuned by changing the central anion or extracting/adding one silver atom. This study provides the facile way to synthesize discrete wheel-shaped multinuclear silver complexes and provides valuable insights into the dynamics of the self-assembly process.