Coumarin phosphorescence observed with N⁁N Pt(ii) bisacetylide complex and its applications for luminescent oxygen sensing and triplet–triplet-annihilation based upconversion
作者:Haiyang Sun、Huimin Guo、Wenting Wu、Xin Liu、Jianzhang Zhao
DOI:10.1039/c1dt10490j
日期:——
A dbbpy platinum(II) bis(coumarin acetylide) complex (Pt-1, dbbpy = 4,4â²-di-tert-butyl-2,2â²-bipyridine) was prepared. Pt-1 shows intense absorption in the visible region (λabs = 412 nm, ε = 3.23 à 104 Mâ1 cmâ1) compared to the model complex dbbpy Pt(II) bis(phenylacetylide) (Pt-2, λabs = 424 nm, ε = 8.8 à 103 Mâ1 cmâ1). Room temperature phosphorescence was observed for Pt-1 (3IL, ÏP = 2.52 μs, λem = 624 nm, ΦP = 2.6%) and the emissive triplet excited state was assigned as mainly intraligand triplet excited state (3IL), proved by 77 K steady state emission, nanosecond time-resolved transient absorption spectroscopy and DFT calculations. Complex Pt-1 was used for phosphorescent oxygen sensing and the sensitivity (SternâVolmer quenching constant KSV = 0.012 Torrâ1) is 12-fold of the model complex Pt-2 (KSV = 0.001 Torrâ1). Pt-1 was also used as triplet sensitizer for tripletâtriplet-annihilation based upconversion, upconversion quantum yield ΦUC up to 14.1% was observed, vs. 8.9% for the model complex Pt-2.
制备了一种 dbbpy 双(香豆素乙酰基)铂(II)络合物(Pt-1,dbbpy = 4,4â²-二叔丁基-2,2â²-联吡啶)。与模型复合物 dbbpy Pt(II)双(苯乙酰基)(Pt-2,δ "abs = 424 nm,δµ = 8.8 Ã 103 Mâ1 cmâ1)相比,Pt-1 在可见光区域显示出强烈的吸收(δ "abs = 412 nm,δµ = 3.23 Ã 104 Mâ1 cmâ1)。通过 77 K 稳态发射、纳秒时间分辨瞬态吸收光谱和 DFT 计算,证实了 Pt-1 的室温磷光(3IL,ÏP = 2.52 μs,δ "em = 624 nm,δP = 2.6%),并将其发射的三重激发态主要归为配体内三重激发态(3IL)。复合物 Pt-1 被用于磷光氧传感,其灵敏度(斯特恩伏尔默淬灭常数 KSV = 0.012 Torrâ1 )是模型复合物 Pt-2 (KSV = 0.001 Torrâ1 )的 12 倍。Pt-1 还被用作基于三重三湮没的上转换的三重敏化剂,观察到的上转换量子产率δUC 高达 14.1%,而模型复合物 Pt-2 为 8.9%。