Syntheses, Crystal Structures and Photophysical Properties of Dinuclear Copper(I) Complexes Bearing Diphenylphosphino-Substituted Benzimidazole Ligands

摘要

Three dinuclear copper(I) complexes (1, 2 and 3) of the form [(PN)Cu]2(μ2-I)2 have been designed and synthesized with 4- diphenylphosphino-benzimidazole (PN) derivatives. X-ray struc- tural analysis shows that the complexes possess one rhombo- hedral Cu2I2 dimer that is coordinated with two PN ligands and exhibits a trans-configuration. At 290 K, the copper complexes exhibit similar broad and featureless emission bands with peak maxima (λmax) at 585 nm, 565 nm and 586 nm, respectively. The temperature-dependent photophysical behaviors accompanied with the theory calculations demonstrate that 1 represents a thermally activated delayed fluorescence behavior at ambient temperature, whereas luminescence of 2 and 3 is phosphor- escence. Moreover, the complexes (1-3) achieve high photo- luminescence quantum yields of 36.9%, 43.0% and 34.0% with relatively short emission decay times of 5.85 μs, 7.99 μs and 5.99 μs, respectively.