Ag44(SR)304−:a silver-thiolate superatom complex

摘要

Intensely- and broadly-absorbing nanoparticles (IBANs)of silver protected by arylthiolates were recently synthesized and showed unique optical properties, yet question of their dispersity and their molecular formulas remained. Here IBANs are identified as a superatom complex with a molecular formula of Ag44(SR)30⁴⁻ and an electron count of 18.This molecular character is shared by IBANs protected by 4-fluorothiophenol or 2-naphthalenethiol. The molecular formula and purity is determined by mass spectrometry and confirmed by sedimentation velocity-analytical ultracentrifugation. The data also give preliminary indications of a unique structure and environment for Ag44(SR)30⁴⁻.