Sodium thiocyanate binding by a 3-aminobenzoic acid based ion pair receptor consisting of a thiourea binding domain

Abstract The ability to recognize weakly coordinating thiocyanate anion was studied using 3-aminobenzoic acid based ion pair receptor (1) consisting of thiourea and crown ether binding domains. UV–Vis and 1H NMR spectroscopic measurements carried out in acetonitrile showed that receptor 1, unlike its urea analog 2, is able to effectively associate weakly coordinating thiocyanate anion (TBASCN) and exhibits a more than six-fold enhancement in the presence of sodium cations (NaSCN). Data obtained from in-solution measurements are in agreement with the X-ray analysis of 1·NaSCN complex and confirms effective sodium thiocyanate association by receptor 1. In the solid state, thiocyanate anion and sodium cation interact directly with the corresponding binding domains.