Urea-functionalized crystalline capsules for recognition and separation of tetrahedral oxoanions

Abstract

The persistent ability of tripodal TREN-based tris-urea receptors (TREN = tris(2-aminoethyl)amine) to self-assemble with a variety of oxoanions into dimeric capsules upon crystallization is reviewed. The capsule crystallization allows for charge-, shape-, and size-selective encapsulation of tetrahedral XO₄ⁿ⁻ anions (n = 2,3), and provides an effective way to separate these anions from competitive aqueous environments.