Visible light-harvesting cyclometalated Ir(III) complexes with pyreno[4,5-d]imidazole C^N ligands as triplet photosensitizers for triplet–triplet annihilation upconversion
作者:Xiuyu Yi、Pei Yang、Dandan Huang、Jianzhang Zhao
DOI:10.1016/j.dyepig.2012.07.020
日期:2013.1
Cyclometalated Ir(III) complexes with pyrenyl-fused imidazole ligands were prepared. The complexes show strong absorption of visible light and long-lived triplet excited state and were used as triplet photosensitizers for triplet–triplet annihilation (TTA) upconversion. Pyreno[4,5-d]imidazole C^N ligand was used to access the long-lived T1 excited state (Ir-1, bpy = 2,2′-bipyridine as the N^N ligand
制备了具有吡啶基稠合的咪唑配体的环金属化的Ir(III)配合物。该络合物显示出对可见光的强烈吸收和长寿命的三重态激发态,并被用作三重态-三重态an灭(TTA)上转换的三重态光敏剂。Pyreno [4,5-d〕咪唑C ^ N配体被用来访问该长寿命Ť 1激发态(IR-1 ,联吡啶= 2,2'-联吡啶作为N 1,N配体。τ Ť = 56.1微秒)。为了提高在可见光范围内的吸收,香豆素衍生N 1,N配体,使用(IR-2 ,ɛ = 51500中号-1 厘米-1在466纳米,τ Ť= 73.9μs)。配合物在室温下显示红色的磷光。Ir-1和Ir-2的T 1激发态被确定为主要是配体内(3 IL)态,而模型配合物(Ir-0)的金属到配体电荷转移(3 MLCT)态。由稳态发射,瞬态吸收,77 K发射光谱和DFT计算证明。该配合物用作三重态光敏剂用于TTA上转换,并且观察到高达23.7%的上转换量子产率。