氧化偶氮苯双席夫碱化合物对Cu~(2+)的比色识别

为得到简便地识别Cu~(2+)的传感器,设计合成了氧化偶氮苯双席夫碱化合物。采用紫外吸收光谱法研究了化合物对Cu~(2+)的配合作用及对As~(3+)、Mo~(6+)、Mn~(2+)、Zn~(2+)、Fe~(3+)、Pb~(2+)、Al~(3+)、Hg~(2+)、Ni~(2+)、Pt~(4+)、Mg~(2+)、Be~(2+)、Sr~(2+)、Cs+、Os4+、Cd~(2+)、Se~(4+)、Cr~(6+)、Co~(2+)、Rb+、Ba~(2+)、V6+、Ca~(2+)等23种金属离子的干扰作用。采用等摩尔的连续变化法(Job-plot),研究了化合物与Cu~(2+)形成配合物的配比。用红外光谱法研究了配合机理。同时研究了在EDTA存在时,化合物对Cu~(2+)的"off-on"性质。结果表明,合成的化合物具有大共轭体系,结构新颖且稳定。化合物可以克服23种金属离子的干扰,对Cu~(2+)的选择性很高。化合物与Cu~(2+)形成1∶1型强发光配合物,可以达到比色(裸眼)识别。在1.32~13.0μmol·L~(-1)范围内,化合物紫外光谱吸光度值与Cu~(2+)浓度呈现良好的线性关系,线性范围宽,最低检出限为2.6×10-7mol·L~(-1)。在EDTA存在时,该配合物释放出Cu~(2+),表现出对Cu~(2+)的"off-on"模式,红外光谱法研究明确了化合物与Cu~(2+)的结合位点。研究结果表明,所合成的氧化偶氮苯双席夫碱化合物可以对Cu~(2+)实现简便易行的比色(裸眼)识别。

Highly Selective Colorimetric Recognition of Copper Ions Based on Bis-Schiff Base Containing An Azoxy Group

In order to obtain copper ion sensors, a bis-Schiff base containing an azoxy group was synthesized.The complexation effect of the compound on Cu2+ was studied, and the interference of 23 metal ions such as As3+, Mo6+, Mn2+, Zn2+, Fe3+, Pb2+, Al3+, Hg2+, Ni2+, Pt4+, Mg2+, Be2+, Sr2+, Cs+, Os4+, Cd2+, Se4+, Cr6+, Co2+, Rb+, Ba2+, V6+, Ca2+ was also studied in MeOH-H2O by UV-Vis spectroscopy.Job-plot method was used to study the ratio of the Cu2+ complex with the compound.The cooperation mechanism was studied by infrared spectrometry, and the "off-on" nature of the compound with copper ion was studied in EDTA.The results indicate that the bis-Schiff base has a large conjugated system, the structure is novel and stable.The bis-Schiff base shows a highly selective response to Cu2+. A clear color change from colorless to yellow is observed upon the addition of Cu2+ to the solution of the receptor in MeOH by naked-eyes and a single selectivity colorimetric recognition.The Job-plot shows that the bis-Schiff base coordinates with Cu2+ to form 1∶1 stable luminescent complex.The UV absorbance of the system shows a good linear relationship with Cu2+ concentration within 1.32-13.0 μmol·L-1, and the detection limit is 2.6×10-7 mol·L-1.The sensing of Cu2+ by this sensor is found to be reversible with the Cu2+ induced color being lost upon the addition of EDTA.The process of titrating Compound 1 with Cu2+ is reversible, and Compound 1 can be used as an off-on switch chemosensor.The complexation mechanism of Compound 1 and Cu2+ was studied by IR spectroscopy, and the binding sites of compound 1 and Cu2+ were identified.