以1-苯基吡唑为主配体的红光Ir(Ⅲ)配合物的合成及光电特性

Synthesis and Optoelectronic Properties of a Red-Emitting Iridium(Ⅲ) Complex Containing 1-Phenylpyrazole

合成了一种新型红色磷光配合物二(1-苯基咪唑)(1-苯基异喹啉)合铱((ppz)2Ir(piq)),通过核磁共振氢谱(1HNMR)对其结构进行了表征,通过紫外-可见(UV-Vis)吸收光谱、荧光光谱、低温磷光光谱、循环伏安法及含时密度泛函理论(TD-DFT)对其光物理性能及能级结构进行了研究.制备了一系列基于(ppz)2Ir(piq)的电致发光器件,研究了(ppz)2Ir(piq)的电致发光性质.结果表明,(ppz)2Ir(piq)的UV-Vis吸收峰主要位于296、342、395和460nm,固态粉末的室温磷光发射峰位于618nm,在2-甲基四氢呋喃(2-MeTHF)溶液中其低温磷光发射峰位于598nm,其三线态能级(ET)为2.07eV.(ppz)2Ir(piq)的最高占据轨道(HOMO),其主要定域于配体ppz和金属Ir(III)上,最低未占据轨道(LUMO)主要定域于配体piq上.(ppz)2Ir(piq)的HOMO和LUMO能级分别为-5.92和-3.62eV.基于(ppz)2Ir(piq)电致发光器件的优化掺杂浓度为8%-12%(w),最大电致发光谱峰位于616nm,最大电流效率约10cd·A-1,最大功率效率为4.44lm·W-1,色坐标保持在(0.65,0.35)附近,是一种潜在的饱和红光磷光材料.

The synthesis, characterization, photophysical and electrophosphorescent properties of iridium（Ⅲ） complex [（ppz）2lr（piq）] （ppz=1-phenylpyrazole, piq=l-phenylisoquinoline） are reported. The structure was defined by proton nuclear magnetic resonance （1H NMR）. The photophysical properties and energy-level structure of [（ppz）21r（piq）] are studied by ultraviolet-visble （UV-Vis） absorption, fluorescence, and phosphorescent spectroscopies at 77 K, cyclic voltammetry （CV）, and time-dependent density functional theory （TD-DFT） calculation. The electroluminescent properties of [（ppz）21r（piq）] using 4,4＇-bis（9-carbazolyl）-1, 1＇-biphenyl （CBP） as a host are investigated. Absorption bands of [（ppz）21r（piq）] are located at about 296,342, 395, and 442 nm. [（ppz）21r（piq）] exhibits red phosphorescent emission with a peak at 618 nm in CH2CI2 solution at room temperature and 598 nm in 2-methyltetrahydrofuran （2-MeTHF） at 77 K, from which its triplet state energy （ET） is estimated to be 2.07 eV. The highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO） levels of [（ppz）2lr（piq）] are -5.92 and -3.62 eV, respectively. A theoretical calculation reveals that the HOMO of [（ppz）glr（piq）] is mainly distributed on ppz and the iridium ion, while the LUMO is mainly centered on piq. Organic light-emitting diodes （OLEDs） containing [（ppz）2 Ir（piq）]- doped CBP emitting layer exhibit an electroluminescence （EL） maximum at 616 nm, an optimized doping concentration of 8%-12% （w）, maximum current efficiency of about 10 cd. A-1, maximum power efficiency of 4.44 Im ·W^-1, and International Commission on Illumination （CIE） coordinates of （0.65, 0.35）. This investigation provides an important experimental basis for the application of [（ppz）21r（piq）] in organic electroluminescent devices.