0D and 1D-dimensional Cu(I)-based halides pyridyltriazoles basis: Synthesis, Structures, and photophysical properties

Three binuclear and two polymeric Cu(I) complexes namely, [Cu2(L1)2Cl2(PPh3)2] (1), [Cu2(L1)2Br2(PPh3)2] (2), [µ-L2(CuCl(PPh3)2)2]∙4MeOH (3), [CuBrL2(PPh3)]n (4) and [Cu2Cl2L2(PPh3)2]n (5) (3,5-bis(pyridin-4-yl)-1H-1,2,4-triazole (L1), 3,5-bis(pyridin-4-yl)-1H-1,2,4-triazole (L2) and 5-(pyridin-4-yl)-3-(pyridin-3-yl)-1H-1,2,4-triazole (L3)) were synthesized and structurally characterized. Binuclear complexes 1–3 show strong green luminescence in the crystals, exhibiting about 50 % photoluminescence quantum yields, while polymeric complexes show moderate emission in yellow region. The emission studies reveal that complexes 1–3 emit TADF from the 1(M + X)LCT state at room temperature because of their small singlet–triplet energy difference. Moreover complex 5 exhibited excellent stimuli-responsive photoluminescent performance in the solid state at room temperature.