新型“开式”环金属铱配合物次氯酸盐荧光探针的合成与应用

Synthesis and Application of a Novel“Switch-on”Cyclometalated Iridium Complex Fluorescent Probe for Hypochlorite Detection

设计合成了一种新型灵敏的荧光化学探针[Ir(bzq)_(2)(L1)](PF_(6))(bzq=苯并喹啉,L1=4'-甲基-2,2'-联吡啶-4-甲醛肟)并进行了详细表征。将该配合物用于对次氯酸盐(ClO-)的荧光测定,发现加入ClO-后,探针溶液的荧光显著增强,在365 nm紫外灯下由暗棕色迅速转变为明亮的橙黄色,可能是配体L1中的肟作为反应位点被ClO-氧化为羧酸,抑制了非辐射衰变过程从而使探针发射出强荧光。在优化实验条件下,探针[Ir(bzq)_(2)(L1)](PF_(6))的荧光强度与ClO-浓度在0.1~210μmol/L范围内呈良好的线性关系,检出限为3.08 nmol/L。荧光探针对ClO-的选择性较好,其它可能的共存离子不干扰测定。采用该方法测定了当地河水中的次氯酸盐,加标回收率为92.4%~103%,结果令人满意,表明该方法可用于实际样品中ClO-的测定。

In this paper,a novel sensitive fluorescent probe[Ir(bzq)_(2)(L1)](PF_(6))(bzq,i.e.benzo⁃quinoline,and L1,i.e.4'-methyl-2,2'-bipyridine-4-formaldehyde oxime)was synthesized and characterized in detail.After adding hypochlorite(ClO-)in[Ir(bzq)_(2)(L1)](PF_(6))system,the fluo⁃rescence of this complex was significantly enhanced because the oxime group on L1 as the reaction site was transformed into the carboxylic acid,resulting in a bright visible orange-yellow light from dark brown under a 365 nm ultraviolet lamp.Under the optimum conditions,the fluorescence inten⁃sity of[Ir(bzq)_(2)(L1)](PF_(6))probe showed a good linear relationship with hypochlorite in the concen⁃tration range of 0.1-210μmol/L,with a detection limit of 3.08 nmol/L.The selective and competi⁃tive experiments revealed that this probe showed better selectivity and sensitivity for ClO-than that for other ions.The proposed method was applied to the detection of ClO-in local river samples with satis⁃factory recoveries of 92.4%-103%,suggesting that the fluorescent probe could be used for analysis of ClO-in practical samples.