Three Luminescent Dinuclear Copper(I) Complexes with P˄N Ligands: Synthesis, Photophysical Properties, DFT Calculations and AIE Behavior

Abstract Three new BPTA‐bridged binuclear copper(I) complexes bearing three different diphosphine ligands, namely, [(Cu I ) 2 (Xantphos) 2 (BPTA)](BF 4 ) 2 ( Cu1 ), [(Cu I ) 2 (Dppp) 2 (BPTA)](BF 4 ) 2 ( Cu2 ), and [(Cu I ) 2 (Binap) 2 (BPTA)](BF 4 ) 2 ( Cu3 ), have been synthesized and characterized. The X‐ray structure analyses of complex Cu3 show that the central copper(I) ion adopts a distorted tetrahedral geometry. Complexes Cu1 and Cu2 exhibit greenish‐yellow emission with excited‐state lifetime (13μs and 27μs) and photoluminescence quantum yields (6.86 % and 0.62 %) at room temperature in the solid state. Emission decay measurement and theoretical calculation suggest that the transition nature of their emission could be assigned to 3 MLCT/ 3 LC excited states. More interesting, complexes Cu1 ‐ Cu3 are weakly emissive in solution but become strongly luminescent in solid state, so it has the aggregation induced emission (AIE) behavior.