Cu(Ⅱ)-席夫碱配合物的合成及其催化活性

Synthesis of Cu(Ⅱ)-Schiff base complex and its catalytic activity evaluation in aqueous solution

在乙醇溶剂中,3,5-二溴水杨醛为母体,与乙醇胺反应合成了席夫碱,随后与铜离子进一步反应生成铜配合物,用元素分析、紫外光谱、红外光谱和X射线光电子能谱等手段来表征其结构和组成,用液相色谱-高分辨飞行时间-质谱联用仪测定了席夫碱的分子量.以铜配合物为催化剂在水相近中性条件下催化H_(2)O_(2)氧化酚类污染物,以苯酚为底物探讨了溶液pH、H_(2)O_(2)用量、反应温度和反应时间等因素对氧化反应的影响.结果表明,在酚类浓度为1.00mmol/L,铜配合物浓度为0.05mmol/L,H_(2)O_(2)浓度为30mmol/L,pH7.6,50℃,5h等条件下,2,4-二氯酚的去除率最大,达84.8%(矿化率7.8%),五氯酚的去除率最小,为29.1%(无矿化).淬灭实验结果表明羟基自由基是该反应体系中的主要活性氧物质.

A Schiff base was synthesized from the reaction between 3,5-dibromosalicylaldehyde and ethanolamine;then its Cu^(2+)-complex was prepared from the reaction between the Schiff base and copper ion.Their structure and chemical composition were characterized by elemental analysis(EA),ultraviolet spectroscopy(UV),Fourier-transform infrared spectro-scopy(FT-IR),and X-ray photoelectron spectroscopy(XPS).The molecular weight of the Schiff base was confirmed by the high resolution liquid chromatograph-time of flight-mass spectrometry(LC-TOF-MS).Catalytic oxidation of phenols by the Cu^(2+)-complex activated hydrogen peroxide(H_(2)O_(2))was evaluated at neutral conditions.To optimize the reaction condition,effects of solution pH,H_(2)O_(2) concentration,reaction temperature,and reaction time were investigated by using phenol as the model contaminant.Under the optimal reaction condition of[Phenols]0=1.00 mmol/L,[Cu^(2+)-complex]0=0.05 mmol/L,[H_(2)O_(2)]0=30 mmol/L,pH 7.6,and 50℃,the removal of PCP was the lowest 29.1%(TOC removal=0),and that of 2.4-DCP was the highest 84.8%(TOC removal=7.8%)within 5 h.Radical quenching experiment results showed that hydroxyl radical(·OH)was the dominant reactive oxygen species(ROS)in the reaction system.