A novel and simple cyanide chemosensor 2-（naphthalen-1-ylmethylene）malononitrile（L） was designed and synthesized via a green chemistry method in water without using any catalyst.The chemosensor showed an excellent sensitivity and selectivity for CN in aqueous solution.The detection limit could be as low as 1.6×10~7 moI/L（0.16μmol/L）,which is far lower than the WHO guideline of 1.9μmol/L cyanide for drink water.
A novel high-yield Schiff base was designed and synthesized as an anion receptor that specifically select HSO3 anions in aqueous solutions of H20/DMSO（15：85, volume ratio）, which can be detected via colorimetry under direct visualization. The sensor exhibited different results for other anions, such as F, CI, Br, I-, H2PO4-, AcO-, HSO4 and C104. The changes in the UV-Vis spectra also show the specific recognition of HSO3 , rather than similar anions H2PO4- and HSO4- in the same aqueous solution. The detection limit of HSO3- was 1×10-6 mol/L.
YANG Wen-long LI Qiao WEI Tai-bao ZHANG You-ming LIN Qi SHI Bing-bing ZHANG Peng
By applying an indirect strategy, a new copper （II） complex of a thiosemicarbazone L has been successfully developed as a colorimetric cbemosensor for the sensitive detection of mercury （II） ions. In the presence of copper （II） ions, the colorless so- lution of L became yellow; however, upon the addition of traces of mercury （II） ions, the yellow color faded to colorless im- mediately. Other ions, including Fe3＋, Ag＋, Ca2＋, Zn2＋, Pb2＋, Cd2＋, Ni2＋, Co2＋, Cr3＋ and Mg2＋ had a negligible influence on the probe behavior. The detection limits were 5.0×10^-6 M and 3.0×10^-7 M of Hg2＋ using the visual color changes and UV-vis changes respectively. Test strips based on Cu-L were fabricated, which could act as a convenient and efficient Hg2＋ test kits.
A non-sulfur chemosensor based on an easy to prepare double naphthalene Schiff base is reported for the colorimetric and fluorometric dual-channel sensing of Hg2+ ions by taking advantage of the twisted intramolecular charge transfer (TICT) mechanism. This work provides a novel approach for the selective recognition of mercury ions. Moreover, this sensor serves as a potential recyclable component in sensing materials and the complex L-Hg2+ (L = 1-[(2-naphthalenylimino)methyl]-2-naphthalenol) can therefore be used as a fluorescent sensor for iodine anions. Notably, the color changes are very significant and all the recognition and recycling processes can be observed by the naked eye.
A new Zn2＋ probe L2-Zn（L2=naphthofuran carbonylhydrazone derivant） was synthesized as a fluores- cence chemosensor for Cu2＋, by which Cuz＋ ion could be detected with high selectivity and sensitivity in a wide pH range via a displacement ＂turn-off＂ signaling strategy. Whereas the coordination between Zn2＋ and L2 resulted in a considerable enhancement of typical luminescence of a naphthalofuran group in complex L2-Zn, the addition of Cu2＋ ion led to a dramatic decrease in the emission intensity of probe L2-Zn at about 503 nm（excitation at 423 nm）. The competitive fluorescent experiments showed that other metal ions, such as Hgz＋, Fe3＋, Ag＋, Ca2＋, Co2＋, Ni2＋, Cd2＋, Pb2＋, Zn2＋, Cr3＋ and Mg2＋ could not impact tile detection of Cu2＋. The detection limit of the novel probe L2-Zn for Cu2~ ion was as low as 2.3× 10 7 mol/L, which is far lower than the guideline value of 1.6× 10-5 mol/L of the United States Environmental Protection Agency.
GUAN Jie ZHANG Peng WEI Taibao LIN Qi YAO Hong ZHANG Youming
A novel smart metal-organic gel（MOG） formed from biscarboxyl-functionalized benzimidazole derivative（D11） in the presence of lead nitrate has been investigated.The critical gel concentration for the formation of MOG was just 0.36 wt%,which exhibits a super gelation capability of D11.The coordination of the metal to the ligand D11 was found to play a vital role in the construction of the supramolecular MOG.Microstructures determined by SEM observation demonstrated that the MOG was formed by intertwined fibrils.Interestingly,the MOG exhibits pH-induced,thermo-induced,and chemical-induced reversible gel-sol transition.Meanwhile,this supramolecular MOG shows desirable absorption ability of methyl orange dye molecules in aqueous solution.
Hong YaoXing-Mei YouQin LinJun-Jian LiYing GuoTai-Bao WeiYou-Ming Zhang
