Three-Dimensional Covalent Organic Frameworks with scu Topology

Three-dimensional (3D) covalent organic frameworks (COFs) exemplify a new generation of crystalline extended solids with intriguing structures and unprecedented porosity. Notwithstanding substantial scope, the reticular synthesis of 3D COFs from pre-designed building units leading to new network topologies yet remains a demanding task owing to the shortage of 3D building units and inadequate reversibility of the linkages between the building units. In this work, by linking a tetragonal prism (8-connected) node with a square planar (4-connected) node, we report the first 3D COF with scu topology. The new COF, namely TUS-84, features a two-fold interpenetrated structure with well-defined porosity and a Brunauer−Emmett−Teller surface area of 679 m2 g-1. In drug delivery applications, TUS-84 shows efficient drug loading and sus-tained release profile.