Series of Viologen-Based Metal–Organic Polyhedra with Photo/Electrochromic Behavior for Inkless Printing and UV Detection

The fabrication of molecular crystalline materials with fast, multistimuli-responsive behavior and the construction of the corresponding structure–activity relationship are of extraordinary significance for the development of smart materials. In this context, three multistimuli-responsive functional metal–organic polyhedra (MOP), {[Dy2(bcbp)3(NO3)1.5(H2O)7]·Cl4.2·(NO3)0.3·H2O}n (1), {[Dy2(bcbp)4(H2O)8]Cl6}n (2), and {[Eu2(bcbp)4(H2O)10]Cl6·H2O}n (3; bcbp = 1,1′-bis(4-carboxyphenyl)-4,4′-bipyridinium), were successfully prepared and characterized. All of the compounds exhibit rapid and reversible photochromic and electrochromic dual-responsive behaviors. Furthermore, benefiting from the well-defined crystal structure and different responsive behaviors, the photoinduced electron transfer (PIET) process and structure–activity relationship were explored. In addition, considering the excellent photochromic performance, function filter paper and smart organic glass were successfully prepared and used for ink-free printing and UV light detection

PEGylated Perylenemonoimide-Dithienylethene for Super-Resolution Imaging of Liposomes

We have designed and synthesized an amphiphilic photoswitchable fluorophore, PEGylated perylenemonoimide-dithienylethene (PEG-PMI-DTE), which exhibits evident bistable photochromism, fluorescence switching, and fatigue resistance. The fine nanostructures of liposomes can be observed directly under super-resolution fluorescent microscopy by aid of the amphiphilic photoswitchable fluorophore as a staining agent, with an optical resolution of 30 nm

Geminal Cross-Coupling of 1,1-Dibromoolefins Facilitating Multiple Topological π‑Conjugated Tetraarylethenes

The cross-coupling reactions have been used in C–C bond formation which can be used extensively in optoelectronic materials for organic light-emitting diodes, organic photovoltaics, and chemical biosensing. Here, we report 2-fold geminal C–C bond formation at 1,1-dibromoolefins via cross-coupling reactions of aromatic boronic esters over Pd catalysts for multiple topological configurations of π-conjugated molecules. We employ a series of recipes from a precursor toolbox to produce π-conjugated macrocycles, conjugated dendrimers, linear conjugated polymers, and multiple conjugated microporous polymers and nanoparticles. The π-conjugated macrocycles, dendrimers, and linear polymers show characteristic aggregation-induced emission properties. The conjugated microporous polymers possess unique porosity of 2–3 nm. The microporous polymer nanoparticles can be redispersed in solution. This universal strategy toward definite topological configurations of π-conjugated molecules enables efficient coupling of aryl bromides with various coupling partners under mild conditions affording multiple topological conjugated systems with abundant optical and optoelectronic interest