Entanglement of Square Nets in Covalent Organic Frameworks.

Two entangled 2D square covalent organic frameworks (COFs) have been synthesized from 4,4',4″,4‴-(9,9'-spirobi[fluorene]-2,2',7,7'-tetrayl)-tetrabenzaldehhyde (SFTB) and -phenylenediamine (PPA) and benzidine (BZD) to form COF-38, [(SFTB)(PPA)], and its isoreticular form COF-39, [(SFTB)(BZD)]. We also report the single-crystal electron diffraction structure of COF-39 and find that it is composed of mutually entangled 2D square nets (). These COFs represent the first examples of entangled 2D COF structures, which, as we illustrate, were made possible by our strategy of using the distorted tetrahedral SFTB building unit.

Bimolecular proximity of a ruthenium complex and methylene blue within an anionic porous coordination cage for enhancing photocatalytic activity.

The charge repulsion between a catalyst and substrate will significantly reduce the contact occurring between them, resulting in low reactivity. Herein, we report an anionic porous coordination cage that is capable of encapsulating both a cationic catalyst and cationic substrate in its cavity at the same time. After encapsulating the [Ru(bpy)]Cl (bpy = bipyridine) catalyst, the cage/catalyst composite serves as an active heterogeneous catalyst for the photo-degradation of methylene blue (MB).

Molecular Weaving of Covalent Organic Frameworks for Adaptive Guest Inclusion.

The synthesis of new isoreticular non-interpenetrated woven covalent organic frameworks (COFs) was achieved by linking aldehyde-functionalized copper(I) bisphenanthroline complexes with benzidine linkers in the presence of a bulky anion, diphenylphosphinate (POPh) to give metalated COF-506-Cu and, upon removal of copper(I), the demetalated COF-506. The structures of these COFs were determined by a combination of powder X-ray diffraction and electron microscopy techniques. Guest-accessibility to the pores of the two frameworks was examined by vapor and dye inclusion studies and compared to the already reported doubly-interpenetrated COF-505-Cu.