Organic Ligand\nExchange: The Chiral Structure–Property\nRegulation of Cuprous Halides

The strategy of organic ligand exchange is proposed to\ntune the\noptical properties of organic–inorganic hybrid cuprous halides.\nIn this work, the chiral ligand (S)-(−)-2,2′-bis(di-<i>p</i>-tolylphosphino)-1,1′-binaphthyl ((S)-Tol-BINAP)\nand achiral triphenylphosphine (PPh<sub>3</sub>) are introduced into\ncuprous halides CuX-PPh<sub>3</sub>-[(S)-Tol-BINAP] (X = Cl, Br, I)\nthrough organic ligand exchange. As a result, the mixed organic ligands\ncan enhance second harmonic generation (SHG) and aggregation-induced\nemission (AIE) optical properties. Moreover, the title compounds exhibit\nprogressively enlarged SHG effects along with heavier halogen substitution\ndue to their stronger polarizability. In the meantime, the reduced\nπ–π stacking interaction of the organic ligand\nwill improve their photoluminescence quantum yield. The experimental\nresults combined with the theoretical calculation clarify the structure–property\nrelationship well. Furthermore, the title compounds have been developed\nfor the application of latent fingerprint detection.