由氯甲酸乙酯和硫氰酸钠经亲核取代反应和异构化合成N-乙氧羰基异硫氰酸酯中间体,再将该中间体与1,6-己二胺经亲核加成反应,合成N,N’-二乙氧羰基-N’’,N’’’-(1,6-亚己基)双硫脲。对其进行元素分析、红外光谱、核磁共振氢谱及碳谱分析。将所得产物配成溶液,分别与Cu2+,Ni2+和Fe3+溶液混合,用紫外可见分光光度计测定产物溶液吸光度的变化,对产物与Cu2+离子的沉淀产物进行红外光谱检测,对比产物与其Cu2+络合物的红外光谱。研究结果表明:具有新型结构的双硫脲可分别与此3种离子发生反应,并表现出对Fe3+的较强选择性。产物与Cu2+生成的络合物为环状螯合物。
The intermediate N-ethoxylcarbonyl isothiocyanate was synthesized from ethyl chloroformate and sodium thiocyanate by nucleophilic substitution reaction and isomerization.Then using this intermediate with 1,6-diaminlhexane as raw materials,the target product N,N'-diethoxycarbonyl-N'',N' ''-(1,6-hexylidene) dithiourea was obtained by nucleophilic addition reaction.The compound was characterized by elemental analysis,infrared spectrum,1HNMR and 13CNMR.The solution of the compound was mixed with Cu2+,Ni2+,Fe3+ solution respectively,and the changes of the absorbance of three compound solutions via UV-Vis spectrophotometer were determined.The precipitate of the compound reacting with Cu2+ ion was analyzed through infrared spectrum.The results show that this dithiourea with new structure can react with three ions separately,and has a best selectivity to Fe3+.Compared with the IR spectral data of compound,the structure of the precipitate is of annular chelate.