Synthesis and anion recognition studies of a dipodal thiourea-based sensor for anions

A new dipodal thiourea-based sensor (L) has been synthesized and its binding affinity toward a variety of anions has been investigated in solution and solid state. The colorimetric studies show a significant color change of L in the presence of fluoride, dihydrogen phosphate, and acetate in DMSO. The data obtained from UV–vis titrations is consistent with the results of the colorimetric observations. As investigated by 1 H NMR titrations, the sensor binds an anion in a 1:1 binding mode showing the binding trend in the order of F � >C l � >B r � >I � for halides and H2PO