Synthesis,Structural Characterization,and Electrophosphorescent Properties of Rhenium(I)Complexes Containing Carrier-Transporting Groups

摘要

Two novel diimine rhenium(I)carbonyl complexes with the formula [Re(CO)3(L)Br],where L = 1-(4-5'-phenyl-1,3,4-oxadiazolylbenzyl)-2-pyridinylbenzoimidazole(1)and 1-(4-carbazolylbutyl)-2-pyridinylbenzoimidazole(2),have been successfully synthesized and characterized by elemental analysis,~1H NMR,and IR spectra.Their electrochemical,photophysical,and electroluminescent behaviors,along with the X-ray crystal structure analysis of 2,are also described.White electrophosphorescent devices were fabricated using 1 and 2 as emitters.The devices based on carbazole-containing(hole-transporting group)2 with the structure ITO/m-MTDATA(30 nm)/NPB(20 nm)/2:CBP(8%,30 nm)/Bphen(20 nm)/Alq_3(20 nm)/LiF(0.8 nm)/AI(200 nm)exhibit Commission Internationale de L'Eclairage coordinates of x = 0.34,y = 0.33 with a maximum brightness of 2300 cd/m2 at 580 mA/cm~2.When a brightness of 1500 cd/m2 appears at 230 mA/cm~2,the devices based on 10 wt % 2 still possess 56% of the maximum efficiency which appeared at 2.7 mA/cm~2.These performances are among the best reported for devices using Re(I)complexes as emitters.By comparison of the electroluminescent properties of the devices based on 1 and 2,we conclude that the introduction of the carbazole group into the ligand improves the performance of 1-doped devices.