A visible light/heat responsive covalent organic framework for highly efficient and switchable proton conductivity

Abstract

In recent years, covalent organic frameworks (COFs) have attracted enormous interest as a new generation of proton-exchange membranes, chemical sensors and electronic devices. However, to design high proton conductivity COFs,...

Ingenious Artificial Leaf Based on Covalent Organic Framework Membranes for Boosting CO2 Photoreduction

“…As shown in Figure S2, no matter which kind of COF membranes, their formation is accompanied by the appearance of the new azine CN stretching (∼1622 cm –1 ) and the disappearance of −CHO stretching (∼1696 cm –1 ) in the aldehydic precursor and −NH 2 stretching (∼3300–3400 cm –1 ) in the amine precursor in FTIR spectra, confirming the formation of imine bonds in the COF membranes. The high-resolution XPS spectra (C 1s and N 1s bands) of the three kinds of COF membranes also exhibit signals at 288.2 and 398.8 eV (Figure S3), referring to imine structure in the COF membranes, which is in accordance with the FTIR results . In addition, the thermal decomposition temperature of all the COF membranes was found to be high up to 450 °C as confirmed by TGA, demonstrating the high thermotolerance of the as-prepared membranous structures (Figure S4).…”

“…The high-resolution XPS spectra (C 1s and N 1s bands) of the three kinds of COF membranes also exhibit signals at 288.2 and 398.8 eV (Figure S3), referring to imine structure in the COF membranes, which is in accordance with the FTIR results. 17 In addition, the thermal decomposition temperature of all the COF membranes was found to be high up to 450 °C as confirmed by TGA, demonstrating the high thermotolerance of the asprepared membranous structures (Figure S4).…”

Magnetic and Electric Properties of Pyrazole-Based Metal–Organic Frameworks Grafted With a Sulfonic Moiety

“…23 The basic prerequisites for inducing magnetic-electrical properties would be generating paramagnetic metal based MOFs with ligand containing functional groups that can facilitate charge activation as well as boosting the charge mobility, preferably through extended hydrogen bonded network. 24 Our recent studies on MOFs, often containing porous channels filled with extensive hydrogen-bonded protic solvents, based on a flexible bispyrazole-based ligand, methylenebis(3,5-dimethylpyrazole) (H 2 MDP) showing interesting magnetic and electrical properties, inspired us to further explore this subject. 25 As such, we report herein the synthesis, structural analysis, and electrical and magnetic properties of two multifunctional MOFs…”

“…Recent studies on electrical properties especially showing proton conductivity highlight the continuous need for generating new MOFs with versatile architectures and add-on features, like grafted polar functional groups . The basic prerequisites for inducing magnetic-electrical properties would be generating paramagnetic metal based MOFs with ligand containing functional groups that can facilitate charge activation as well as boosting the charge mobility, preferably through extended hydrogen bonded network . Our recent studies on MOFs, often containing porous channels filled with extensive hydrogen-bonded protic solvents, based on a flexible bispyrazole-based ligand, methylenebis­(3,5-dimethylpyrazole) (H 2 MDP) showing interesting magnetic and electrical properties, inspired us to further explore this subject …”

Photoexcited Anhydrous Proton Conductivity in Coordination Polymer Glass

“…Ion-switching materials in the solid state are classified as shown in Figure . Organic polymers with photoresponsive side groups are used (Figure A). , Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) are regarded as promising platforms due to their diverse structural motifs and tunable properties (Figure B). − Responsive moieties can be either grafted onto the frameworks as linkers or introduced as guest molecules. , Although the switching mechanisms involve photoisomerization of framework components, as observed in electronic switching MOFs, approaches to achieving photoswitchable protonic conductivity have relied mainly on perturbing the connectivity of the ion-conductive guest molecules − rather than modifying the electronic structures. , For example, the trans – cis photoisomerization of azobenzene side groups in surface-mounted MOF restricts the migration of H + -conducting guest molecules and thus lowers the conductivity . Similarly, photoisomerization of nitric oxide in Cs 1.1 Fe 0.95 [Mo­(CN) 5 (NO)] 4 ·H 2 O breaks the connectivity of H-bonding networks of water guest molecules …”