A new colorimetric sensor based on semithiocarbazone for some anions: 2-(1,3-dioxo-1,3-dihydro-2H-inden-2-ylidene)-N-phenylhydrazine-1-carbothioamide

Carbazones are molecules containing important functional groups in designing anion chemosensors due to proton donor and acceptor sites in their structures. In this paper, we synthesize a novel colorimetric receptor with 1,3 dioxo-indene and thiosemicarbazone moieties by the reaction of ninhydrin and 4-phenyl-thiosemicarbazide in quantitative yield. We then identify its structure by means of FT-IR, 1H-NMR, 13C-NMR, and MS spectroscopic techniques. Moreover, we observe the reaction of the title compound with biologically important F¯, OAc¯, CN¯, H2PO4¯, and OH¯ anions in the presence of other anions, such as Cl¯, Br¯, I¯, SCN¯, and OCl¯ in dimethylsulfoxide solution through a color change from yellow to orange-red that can easily be distinguished even by the naked eye under ambient light. Finally, we evaluate the anion-sensing ability of the title compound via UV-vis spectroscopic studies.