Synthesis of Calix[4]arene-Based Thiourea Derivatives for Extraction of Toxic Dichromate and Arsenate Ions

In the environment, the presence of toxic oxyanions such as Cr(VI) and As(V), especially in drinking water, creates serious hazards to human health. For efficient and selective detection of these species; novel calix4]arene-based thiourea derivatives which obtained using p-tert-butylcalix4]arene as starting material have been prepared from m-aniline or o-aniline or o-aminophenol in moderate yield. The structures of all new synthesized compounds obtained from these reactions were determined by using FTIR, ¹H, and ¹³C NMR spectroscopy. The complexing properties of calix4]arene-based thiourea derivatives have been studied towards the As(V) and Cr(VI). It was found that calix4]arene-based thiourea derivative 5,11,17,23-tetra-tert-butyl-25,27-bis(o-amino-phenylthioureido propoxy)-26,28-hydroxycalix4]arene is an effective extractant for carrying HCr₂O₇^2? anions.