Ion pair binding by an l-tyrosine-based polymerizable molecular receptor

Abstract

Two new multitopic salt receptors based on the L-tyrosine scaffold were synthesized using a simple approach. Both receptors consisted of cation and anion binding domains, as well as a polymerizable function. The anion, cation and salt binding properties of these receptors were studied spectrophotometrically in acetonitrile solution. The collected data revealed the stronger association of receptors with ion pairs relative to single anions. The highest enhancement in salt binding was found for receptor 1, which was equipped with a urea-based anion binding site. Sodium coordination with the cation binding domain and carbonyl urea group of the receptor was found to be responsible for the salt binding enhancement. New functional polymers containing the receptor units were synthesized and characterized. A preliminary extraction study of these receptors and copolymers is also presented.