A dual-stimuli responsive small molecule organic material with tunable multi-state response showing turn-on luminescence and photocoloration

Abstract

A multiple responsive organic small molecular material has been developed, which exhibits dual pathway photoreactions and gives turn-on luminescence and photocoloration under different light sources.

Three birds, one stone – photo-/piezo-/chemochromism in one conjugated nanoporous ionic organic network

“…14 In the UV-Vis diffuse reflectance spectra, photoirradiation creates broad absorption bands in 440–800 nm with a shoulder at 740 nm. Such photo-induced absorption changes are similar to a previous observation in well-studied 4,4′-bipyridinium (viologen) derivatives,15 while these changes are rarely observed in 4,4′-bpe derivatives in the solid state 16. The UV-Vis spectrum of the irradiated sample is highly similar to that of the N -methyl-4-[ trans -2-(4-pyridyl)ethenyl] radical (Mebpe) obtained by electrochemical reduction in solution,17 which points to the stable radical state of the irradiated sample.…”

Gemini-Type Supramolecular Amphiphile Based on a Water-Soluble Pillar[5]arene and an Azastilbene Guest and Its Application in Stimuli-Responsive Self-Assemblies

“…First, the single crystal structure of compound G1 was obtained by slow diffusion of 1,4-dioxane vapor into water solutions. As shown in Figure , G1 formed an antiparallel stacking structure by cation−π interaction between pyridinium and pyridyl groups of the adjacent molecules, with the closest centroid–centroid distances of 3.80 and 3.66 Å, respectively.…”

Distinct and Selective Amine- and Anion-Responsive Behaviors of an Electron-Deficient and Anion-Exchangeable Metal–Organic Framework

“…To form the 3D framework, each chain is connected to four others through the coordination between the third carboxylate group of the ligand from one chain and the Eu 4 cluster from another chain. From the topological point of view, with the SBU regarded as 6-connected node and each ligand as 3-connected node, the 3D framework can be simplified to a 3,6connected net with point symbol {4.6 2 } 2 {4 2 .6 10 ). 50 Two identical frameworks related by translation along the a-axis interpenetrate each other to occupy the space in individual frameworks (Figure 1e).…”

“…Driven by the increasing application need in various fields such as artificial intelligence, environmental protection, and medical diagnosis, there has been an upsurge in the study of the smart materials that can sense external stimuli and meanwhile output perceptible or processible signals. − The sensory materials that respond by changing color or luminescence are vigorously sought because the optical changes are easy to detect by either the naked eye or convenient instrumental methods. − Among many candidates, metal–organic frameworks (MOFs), a relatively new class of porous crystalline hybrid materials, have attracted much attention because of their high versatility in functionalization through modification at the metal nodes, the organic linkers, and the pores. − In particular, the variable porous frameworks can be designed with specific electronic properties to afford responsivity to specific chemicals through host–guest interactions. − Because photoluminescent properties can be relatively easily accessed and tuned through varying the metal and/or organic ingredients and emissive excited states are sensitive to external chemical stimuli, a large number of MOFs have been demonstrated to be capable of sensing inorganic or organic species through luminescent changes. − The chromic MOFs that show reversible color response to external chemical stimuli are much less common because the chromic processes need strong interactions between chromophores and stimuli to alter the ground state. In general, strong interactions should be conductive to the sensing selectivity, but the strength should be controlled when reversibility is desired.…”