含三氟乙酰苯基喹啉配体的铱配合物的合成及其电致发光性能

Synthesis and Electroluminescence Properties of Iridium Complex Based on Trifluoroacetylphenyl Quinolone Ligand

通过2-(4′-三氟乙酰苯基)-4-苯基喹啉(tfapqH)与三氯化铱反应生成了二氯桥中间体,然后用吡啶-2-甲酸(picH)解离得到双环金属铱配合物Ir(tfapq)_2pic。Ir(tfapq)_2pic在二氯甲烷中的发光波长为584 nm,量子产率约为0.846,磷光寿命为1.211μs,比没有三氟乙酰修饰的铱配合物波长蓝移的10 nm,量子效率提高了约5%,磷光寿命降低了0.286μs,辐射跃迁加快,半波宽度降低了约26%,色纯度提高。其HOMO能级为-5.405 eV,LUMO能级为-3.277 e V,能级相对于未修饰的配合物都有所降低,且HOMO降低更明显,总的效果是能级差增加。Ir(tfapq)_2pic 10%的热失重温度为301℃,比未修饰铱配合高近50℃。当Ir(tfapq)_2pic以2%质量浓度掺杂于PVK-PBD中做成电致发光器件时的效率最高,电致发光波长为594 nm。器件的启明电压为7.3 V,最大亮度为8 571 cd·m^(-2),最大外量子效率为12.65%,对应的流明效率为22.14 cd·A^(-1)。色坐标是(0.58,0.40)。

A cyclometallated IrⅢ-μ-chloro-bridged dimer was synthesized by the reaction of a trifluoroacetylphenyl quinoline derivative and Ir Cl-3. Then bicyclometalated iridium complex Ir（tfapq）_2pic was synthesized by the reaction between dimer and picolinic acid. Ir（tfapq）_2pic emitted a strong phosphorescence centered at 584 nm in a CH_2Cl_2 solution. Its lifetime is 1.211 μs and quantum yield is approximately 0.846 in a CH_2Cl_2 solution.Compared with the unmodified iridium complex, Ir（tfapq）_2pic have a blue shift emission wavelength, sharp peak,higher quantum yield and shorter lifetime. The HOMO energy level is-5.405 e V and LUMO is-3.277 e V, which both lower than that of unmodified iridium complex and the greater energy band. The 10% weight loss temperature of Ir（tfapq）_2pic is 301 ℃, which 50 ℃ higer than that of unmodified iridium complex. The organic light-emitting device based on Ir（tfapq）_2pic（2wt% doped in PVK-PBD film） exhibits the best efficiency. It′s peak electrophosphorescence wavelength is 594 nm. Its maximum external quantum efficiency is 12.65% and the corresponding efficiency is 22.14 cd·A^（-1）. The maximum luminance is 8 571 cd·m^（-2）. The turn-on voltage is 7.3 V with the Commission Internationale de L′Eclairage（CIE） coordinates of（0.58, 0.40）.