[Ir（F2ppy）2（Br2bpy）]+PF-6配合物的合成、晶体结构及光物理性能测试

Synthesis, Crystal Structure and Light-Physical Properties of Bis-(μ)-Chlorotetrakis-(2-(2,4-difluorophenyl) Pyridinato C^2,N) Diiridium(Ⅲ) Complex

采用氯桥二聚体(F2ppy)2Ir(μ-Cl2)Ir(dfppy)2、辅助配体4,4′-二溴-2,2′-联吡啶(Br2bpy)和阴离子六氟磷酸根(PF-6)合成了一种阳离子型铱配合物[Ir(F2ppy)2(Br2bpy)]+PF-6,并通过元素分析、核磁共振谱(NMR)、红外光谱(FT-IR)及质谱(MS)分析确定了配合物的分子结构,并且首次测定了其晶体结构。结果表明,该配合物结晶于单斜晶系,P21/n空间群,a=0.98612(9) nm,b=2.2240(2) nm,c=1.47121(14) nm,α=90°,β=98.574(2)°,γ=90°,V=3.1905(5) nm3, C32H18Br2F10IrN4P,分子量Mr=1031.49,密度Dc=2.147 mg·m-3,μ(Mo Kα)=6.831 mm-1,F(000)=1960,横型拟合性GOF=1.029,Z=4,可观测衍射点的残差因子R值:R1=0.0321和wR2=0.0741且I>2σ(I)。阳离子型铱配合物[Ir(F2ppy)2(Br2bpy)]+PF-6为电中性八面体配合物, Ir-C键的平均长度为0.2018(3) nm,而Ir-N(C^N配体)键的平均长度为0.2052(3) nm, Ir-N(N^N配体)键的平均长度为0.2138(3) nm。该铱配合物的紫外可见吸收光谱和光致发光光谱的研究表明,其常温最大发射位于551 nm处,显示发射强烈的黄绿光,初步推测该磷光发射可能来自金属到环金属配体和辅助配体的电荷转移(MLCT)跃迁。

A chemical technique was developed for batch synthesis of Bis-(μ)-chlorotetrakis-(2-(2,4-difluorophenyl) pyridinato C2,N) diiridium(III), an organometallic light-emitting molecule for organic light-emitting diode(OLED). The process involved cycometalation of chloride-bridged dimer(F2ppy)2Ir(μ-Cl2)Ir(dfppy)2 with 4,4′-dibromo-2,2′-bipyridine by hexafluorophosphate acid to produce the desired compound in a batch scale. The chemical structure of Bis-(μ)-chlorotetrakis-(2-(2,4-difluorophenyl) pyridinato C2,N) diiridium(III) was verified by elemental analysis, nudear magnetic resonance spectroscopy(NMR(1H)), Fourier transform infrared spectroscopy(FT-IR) and mass spectrum(MS) along with single crystal X-ray diffraction(XRD) data. The results showed that [Ir(F2ppy)2(Br2bpy)]+PF-6 crystallized in monoclinic space group P21/n with a=0.98612(9) nm, b=2.2240(2) nm, c=1.47121(14) nm,α=90°,β=98.574(2)°,γ=90°, V=3.1905(5) nm3, C32H18Br2F10IrN4P, Mr=1031.49, Dc=2.147 mg·m-3,μ(Mo Kα)=6.831 mm-1, F(000)=1960, GOF=1.029, Z=4, the final R1=0.0321 and wR2=0.0741 for I>2σ(I). The synthesized [Ir(F2ppy)2(Br2bpy)]+PF-6 was an electrically neutral octahedral complex. The average Ir-C, Ir-N(C^N) and Ir-N(N^N) bone lengths were found to be 0.2018(3) nm, 0.2052(3) nm and 0.2138(3) nm, respectively. The green-yellow-emission at room temperature peaked at 551 nm, and it was supposed that phosphorescence might originate from the mixture of the MLCT(metal-to-ligand charge transfer) transition.