2,2′-联嘧啶桥联的双金属铱(Ⅲ)配合物的制备及催化性能

Preparation and catalytic properties of 2,2’-bipyrimidine bridged dinuclear cyclometalated iridium(Ⅲ) complexes

为了研究配体对双金属中心配合物性质的影响,合成了4个2,2′-联嘧啶桥联的双金属铱(Ⅲ)配合物[Ir(C^N)2(bpym)Ir(C^N)2](PF6)2,其中C^N分别为2-苯基-吡啶(ppy)、2-(4-甲基苯基)-吡啶(tpy)、2-(2,4-二氟苯基)-吡啶(dfppy)和2-噻吩-吡啶(thpy);利用核磁共振氢谱,高分辨质谱和元素分析对其结构进行了表征,利用紫外-可见光谱和循环伏安对其光物理及电化学性质进行表征。结果表明:金属铱上的配体对2,2′-联嘧啶桥联的双金属铱(Ⅲ)配合物性能有影响,通过改变配体上的电子云密度,可以调控2,2′-联嘧啶桥联的双金属铱(Ⅲ)配合物的光物理性质与电化学性质;同时,还测试了2,2′-联嘧啶桥联的双金属铱(Ⅲ)配合物对过硫酸氢钾活化性能,发现2,2′-联嘧啶桥联的双金属铱(Ⅲ)配合物能有效地活化过硫酸氢钾降解低浓度的布洛芬。同时,对以2-噻吩-吡啶作为配体合成的双金属铱配合物的降解条件进行了考查,使用20 mg配合物活化200 mg过硫酸氢钾,能够在8 h左右降解1 200 mL质量浓度为20 mg/L的布洛芬溶液。

Four dinuclear cyclometalated iridium(Ⅲ) complexes with bridging 2,2’-bipyrimidine [Ir(C^N)2(bpym)Ir(C^N)2](PF6)2(C^N = ppy, 2-phenylpyridinato;tpy,(2-p-tolyl)pyridinato;dfppy, 2-(2,4-difluorophenyl)pyridinato;thpy, 2-thienylpyridinato), were synthesized, their structures were determined by ~1H NMR, high resolution mass spectrometry, and elemental analysis. Their UV-vis spectra and electrochemical behaviors show variation due to the change of the cyclometalated ligands. At the same time, the activation performance of 2,2’-bipyrimidine-bridged bimetallic iridium (Ⅲ ) complexes on potassium persulfate was also tested. It was found that 2,2’-bipyrimidine-bridged bimetallic iridium(Ⅲ) complexes can effectively activate potassium persulfate to degrade low concentration ibuprofen. At the same time, the degradation conditions of the bimetallic iridium complex synthesized with 2-thiophene pyridine as ligand were investigated. Using 20 mg of the complex to activate200 mg potassium persulfate, 1 200 mL ibuprofen solution(20 mg/L) could be degraded in about 8 h.