Synthesis and crystal structure of a highly selective colorimetric and fluorometric sensor for hydrogen sulfide

A novel Cu(II) complex chemosensor for hydrogen sulfide with azo as the colorimetric group has been synthesized. The complex and ligand crystals were obtained and the molecular structures were characterized by X-ray diffraction and Electrospray ionization High resolution mass spectrometer (ESI-HRMS). The photophysical and recognition properties were examined. The complex can recognize S2-, with an obvious color change from yellow to red based on a copper ion complex displacement mechanism. By contrast, no obvious changes were observed in the presence of other anions (AcO-, H2PO4-, F-, Cl-, Br- and I-). We present a simple, easily prepared, yet efficient, inorganic reaction-based sensor for the detection of S2-. The complex should have many chemical and analytical applications in the sensing of hydrogen sulfide.