Circularly Polarized Phosphorescence from Cocrystallization of Atomic Precise Silver Nanoclusters with Tartaric Acid

Abstract Recently, advanced optical materials with circularly polarized phosphorescence (CPP) have attracted much attention. However, such materials are limited due to the difficulty of preparation and the scarcity of precursors. Herein, CPP materials are constructed for the first time using water‐soluble, pseudo‐chiral silver nanoclusters with atomic precision ((NH₄)₉ [Ag₉ (mba)₉], H₂mba = 2‐mercaptobenzoic acid, abbreviated to Ag₉‐NCs hereafter). Induced by the complexation of l‐ or d‐tartaric acid (TrA) through hydrogen bonding, Ag₉‐NCs crystallize from aqueous solutions, during which the chirality of the hybrid is amplified and the phosphorescence of Ag₉‐NCs is enhanced. It is speculated that the chiral transfer from TrA to Ag₉‐NCs is the main source of the well‐defined circular dichroism signals with good repeatability. The Ag₉‐NCs/TrA cocrystals exhibit good CPP performance with dissymmetric factors up to 1.05 × 10⁻², which is the highest value for metal NCs‐based CPP materials. This work is expected to be an inspiration for preparing metal NCs‐based CPP materials by supramolecular strategy. The so‐obtained organic–inorganic CPP materials can find a variety of applications in optoelectronic devices.