Oxidative cyclization of thiosemicarbazone: an optical and turn-on fluorescent chemodosimeter for Cu(ii)
作者:Arghya Basu、Gopal Das
DOI:10.1039/c0dt01549k
日期:——
A weakly fluorescent thiosemicabazone (L1H) was found to be a selective optical and “turn-on” fluorescent chemodosimeter for Cu2+ ion in aqueous medium. A significant fluorescence enhancement along with change in color was only observed for Cu2+ ion; among the other tested metal ions (viz.Na+, K+, Mg2+, Ca2+, Cr3+, Zn2+, Cd2+, Hg2+, Pb2+, Ag+, Ni2+, Co2+, Fe3+ and Mn2+). The Cu2+ selectivity resulted from an oxidative cyclization of the weak fluorescent L1H into highly fluorescent rigid 4,5-dihydro-5,5-dimethyl-4-(naphthalen-5-yl)-1,2,4-triazole-3-thione (L2). The signaling mechanism has been confirmed by independent synthesis with detail characterization of L2.
一种弱荧光的硫半胱氨酸(L1H)被发现作为一种选择性光学和“开关式”荧光化学传感器,用于在水相中检测Cu2+离子。只有在Cu2+离子存在时,才观察到显著的荧光增强和颜色变化;而在其他测试的金属离子(如Na+、K+、Mg2+、Ca2+、Cr3+、Zn2+、Cd2+、Hg2+、Pb2+、Ag+、Ni2+、Co2+、Fe3+和Mn2+)中并未观察到这种现象。Cu2+的选择性源于弱荧光L1H的氧化环化,形成高度荧光的刚性化合物4,5-二氢-5,5-二甲基-4-(萘-5-基)-1,2,4-三唑-3-硫酮(L2)。信号机制已经通过独立合成和L2的详细表征得到了确认。