Uranyl-based Metal-Organic Framework Featuring an Eight-connected U4L2 Cage for Guest Capture

Abstract

A novel (3, 6)-connected uranyl-based MOF (IHEP-50) was synthesized by a judicious combination of UO22+ and polycarboxylic acid, 4,4',4'',4''',4'''',4'''''-(((1,3,5-triazine-2,4,6-triyl)tris(azanetriyl))hexakis(methylene))hexabenzoic acid (H6DTPCA). Two DTPCA6- ligands are connected together via four uranyl cations to form a lantern-shaped cage U4L2, which is further connected with other eight equivalent ones to form the 3D porous framework with two kinds of 1D channels. These large pore structures give it a certain potential for guest molecules capture. Adsorption experiments indicate that IHEP-50 can selectively-remove positively charged dyes over negatively charged and neutral ones. In addition, IHEP-50 demonstrates notably adsorption performance for gaseous iodine, achieving a maximum adsorption capacity of 253.5 mg·g-1.