Synthesis and anion recognition of molecular tweezers receptors based on acyl-thiourea

Three title compounds were designed and synthesized in high yields as novel and simple anion receptors. They had a higher selectivity for F(-) over AcO(-). The binding properties for anions of the receptors were examined by UV-Vis and (1)H NMR spectroscopy. The spectrographic data indicate that a 1:1 stoichiometry complex is formed between the receptors and the anions through hydrogen bonding interactions in DMSO solution. In addition, these molecular tweezers receptors have more binding points of anions, larger association constant, and better recognition ability. They can be used as better recognition receptors for F(-) and CH(3)COO(-).