Chloride assisted supramolecular assembly of a luminescent gigantic cluster: [Ag216S56Cl7(CCPh)98(H2O)12]− with pseudo-Th skeleton and five-shell arrangement

Abstract

Using a chloride-assisted supramolecular building-block approach, we have employed the molecular Cl@Ag_m(CCPh)_n entity in the construction of a gigantic cluster namely [Ag₂₁₆S₅₆Cl₇(CCPh)₉₈(H₂O)₁₂][Ag₃(imidazole)(H₂O)₄](SbF₆)₂ (1), which contains the largest discrete organometallic cluster investigated by X-ray crystallography. Based on an icosahedral Cl@Ag₁₂ kernel, this spheroidal cluster features an unprecedented five-shell structure Cl@Ag₁₂@S₁₂@Ag₃₂@S₄₄Cl₆@Ag₁₇₂ with idealized T_h symmetry. The MALDI-MS, 1D, 2D ¹H NMR, electronic absorption, emission spectra and HR-TEM of 1 were measured. Compound 1 shows intense red luminescence in solution at room temperature (QY = 4.7% in CH₂Cl₂), in addition to its 3.4 nm diameter, which makes it a unique example that fills the gap between small luminescent silver clusters and large luminescent silver nanoparticles.