The effective capture and storage of volatile molecular iodine from nuclear waste is of great significance. Covalent organic frameworks (COFs) are a class of extended crystalline porous polymers that possess unique architectures with high surface areas, long-range order, and permanent porosity. Substantial efforts have been devoted to the design and synthesis of COF materials for the capture of radioactive iodine. In this review, we first introduce research techniques for determining the mechanism of iodine capture by COF materials. Then, the influencing factors of iodine capture performance are classified, and the design principles and strategies for constructing COFs with potential for iodine capture are summarized on this basis. Finally, our personal insights on remaining challenges and future trends are outlined, in order to bring more inspiration to this hot topic of research.

A simple and green method of visible light driven photocatalytic E to Z isomerization of alkenes has been developed. A variety of (Z)-alkenes can be prepared in the presence of visible light, without any additional photocatalyst. This protocol features photocatalyst-free conditions, which are mild, tolerant, and operationally simple, and is easy to implement.

The incorporation of photoactive units into metal–organic frameworks (MOFs) is of particular interest due to their ability to endow the MOFs with additional properties such as photomagnetism, photomodulated electrical conductivity, and photocatalytic properties. Perylenediimides (PDIs), as a class of organic dye molecules with strong visible-light absorption ability and high photochemical activity, have attracted considerable interest because of their consecutive photoinduced electron transfer processes for the generation of energetic PDI radical anions. In this context, a novel photoactive MOF based on a perylenediimide derivative, Zn₂(diPyPI-Cl₄)(NDC)₂·3DMF (MOF 1) (diPyPI-Cl₄ = N,N′-bis(pyridyl)-1,6,7,12-tetrachloroperylene-3,4,9,10-tetracarboxy bisimide, H₂NDC = 2,6-naphthalenedicarboxylic acid), has been successfully constructed, which exhibits a porous three-dimensional framework with a pcu topology. MOF 1 that acts as an efficient and recyclable electron-transfer photocatalyst is applied for boosting the iodoperfluoroalkylation of alkenes and oxidation of amines to imines under mild conditions with high yields and excellent substrate application ranges. This photocatalyst has the advantages of high efficiency, low catalytic loading and easy availability, which is highly feasible from a synthetic point of view.

Host–guest systems based on donor–acceptor interactions have attracted considerable attention as a new platform for the preparation of luminescent metal–organic frameworks (MOFs). However, reasonable design and modulation of donor–acceptor interactions with charge transfer based fluorescence remains a challenge owing to the elaborate self-assembly process of acceptor and donor components. Taking into account the design principles of the host–guest system, a well-defined MOF with an electron-deficient nature should be an ideal host for the building of charge transfer based fluorescent materials. Herein, we have successfully fabricated a suite of host–guest materials (MOFs 2–8) exhibiting charge transfer based fluorescence by virtue of the interactions between electron-rich naphthalene derivatives and an electron-deficient naphthalene diimide-based MOF (MOF 1) as the donor and acceptor, respectively. Profiting from the clear naphthalene derivatives to electron-deficient MOF framework charge transfer interactions, these host–guest materials exhibit color-tunable emissions over a wide range by rational selection of naphthalene derivative molecules. Furthermore, electronic structure calculations reveal that the multicolor emissions of the newly synthesized MOFs depend on the HOMO energy level/ionization potential of naphthalene derivatives. This work provides a promising strategy for the assembly of various novel charge-transfer fluorescent materials as potential luminophores.