Alkynyl-Stabilized Superatomic Silver Clusters Showing Circularly Polarized Luminescence

Abstract

We report a new enantiomeric pair of superatomic silver clusters, <b>R/S-Ag</b>_<b>17</b>, prepared from chiral alkynyl ligands. <b>R-Ag</b>_<b>17</b> and <b>S-Ag</b>_<b>17</b> possess <i>C</i>₃ symmetry and emit near-infrared (NIR) light with a quantum yield (QY) of 8.0% under ambient condition as well as NIR circularly polarized luminescence (CPL) as a result of the chirality of the excited states. Both experiments and theoretical calculations indicate for the first time that the CPL originates from transitions between superatomic 1P_<i>z</i> (along the <i>C</i>₃ axis) and 1S orbitals. This work opens a new avenue for CPL-active metal nanoclusters by utilizing chiral alkynyl ligands and enlightens the chirality transfer from chiral protecting ligands to superatomic states in metal clusters.