Highly selective and sensitive colorimetric probe for hydrogen sulfide by a copper (II) complex of azo-dye based on chemosensing ensemble approach

A copper (II) complex of azo-dye (Cu-1) has been synthesized by the reaction of 1-(2-pyridylazo)-2-naphthol (1) with copper (II) chloride. The complex Cu-1 is able to selectively sense hydrogen sulfide over other anions followed by the release of compound 1 to give a remarkable change of UV–vis absorption at neutral pH in aqueous solution.

Graphical abstractA copper (II) complex of azo-dye (Cu-1) has been synthesized by the reaction of 1-(2-pyridylazo)-2-naphthol (1) with copper (II) chloride. The complex Cu-1 is able to selectively sense hydrogen sulfide over other anions followed by the release of compound 1 to give a remarkable change of UV–vis absorption at neutral pH in aqueous solution.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Cu-1 can be utilized as a colorimetric chemosensor for detection of H2S at neutral pH in aqueous solution. ► The blue-shifted absorption band could be attributed to the released 1 from the complex Cu-1 by adding Na2S to capture the Cu2+. ► Cu-1 showed excellent selectivity toward H2S over the other competitive anions.