海滨稚子

Self-standing, flexible, continuous, and crack-free covalent-organic-framework membranes (COMs) are fabricated via a simple, scalable, and highly cost-effective methodology. The COMs show long-term durability, recyclability, and retain their structural integrity in water, organic solvents, and mineral acids. COMs are successfully used in challenging separation applications and recovery of valuable active pharmaceutical ingredients from organic solvents.

The rational design of a flexible molecular box, oAzoBox⁴⁺, incoporating both photochromic and supramolecular recognition motifs is described. We exploit the EZ photoisomerization properties of azobenzenes to alter the shape of the cavity of the macrocycle upon absorption of light. Imidazolium motifs are used as hydrogen-bonding donor components, allowing for sequestration of small molecule guests in acetonitrile. Upon EZ photoisomerization of oAzoBox⁴⁺ the guest is expelled from the macrocyclic cavity.

One ring to rule them all … and in the darkness bind them: A photoresponsive tetracationic macrocycle features a facile three-step synthesis and makes possible the noncovalent binding of a set of guest molecules, including N-oxide and carboxylate derivatives. The guest molecules can be actively released by UV light irradiation in a remote fashion.

An approach to transforming amorphous organic networks into crystalline covalent organic frameworks (COFs) with retention of the colloidal nanosize and uniform morphology is presented. Specifically, Fe₃O₄ nanoclusters are encapsulated by a disordering polyimine network via the Schiff-base reaction. The formed imine bonds could be reconstructed under thermodynamic control to reform the polyimine networks into imine-linked COFs in situ. Such a core–shell microsphere exhibits the uniform size and spherical shape, controllable COF shell thickness, accessible surface modification, and improved solution dispersibility as well as maintenance of high surface area, periodic micropores, and superior magnetic responsiveness. Additionally, the photothermal conversion effect is demonstrated for the first time on the nanoCOF layers upon exposure to near infrared light, providing convincing evidence for potential use in phototherapy.

Disorder-to-order: Dynamic imine exchange is manipulated to transform an amorphous polyimine network into a crystalline covalent organic framework (COF) on an Fe₃O₄ nanocluster. The resulting composite microsphere has a shell with hexagonal micropores, periodic opening channels, and adjusted thickness and surface natures. The COF shell gives rise to increased photothermal conversion efficiency, for phototherapy.

The improvement of molecular ordering in conducting polymers from disordered aqueous solution state to highly ordered solid state is investigated by K. Lee and co-workers on page 8625. A well-ordered structure, like a wall, can be formed by painting a mixture solution of PEDOT:PSS with an ionic liquid and then evaporating the water solvent. The different colors in the wall represent units of conducting PEDOT (positively doped) (blue), anionic PSS (orange), the cation of the ionic liquid (yellow), and its counter anion (red). The lighting by the lamp indicates the highly conducting state of PEDOT:PSS, which results from its crystalline formation.

Liquid lunch anyone?Ethylene produced in situ from ethanol dehydration over zeolite is used for the catalytic conversion of biomass-derived furans into aromatic compounds by Diels–Alder cycloaddition. In their Communication on page 13061 ff., G. Mpourmpakis, S. C. E. Tsang et al. describe a rapid and renewable one-pot synthesis of aromatic compounds using liquid ethanol as a source of dienophile instead of pressurized ethylene gas.