Bidirectional enhancement of output performance of nanogenerators by M-COFs materials.

The emergence of nanogenerators, which have the ability to capture mechanical energy from the environment and to collect and transmit tiny energy, is rapidly becoming a hot research topic. The performance of electrode materials is the key to the efficiency of nanogenerators. Covalent organic skeletons (COFs), a class of crystalline organic porous materials with the advantages of large specific surface area, high porosity, tunable structure, and flexible tailorability, have very significant advantages in being used as nanogenerator materials.

Multi-F-Structured MOF Materials Enhance Nanogenerator Output Performance for Corrosion Protection of Metallic Materials.

MOF (metal organic framework) materials have been used as functional materials in a number of fields due to their diverse spatial tunability, which produces rich porous structures with stable and continuous pores and a high specific surface area. A triboelectric nanogenerator can convert trace mechanical energy into electrical energy, and the application of MOF materials to triboelectric nanogenerators has been intensively studied. In this work, we report on two MOFs with similar spatial structures, and the modulation of the end microstructures was achieved using the difference in F content.

Directional design of carboxylic acid coordination number fine-tuned space structure to improve the output performance of nanogenerators.

The emergence of nanogenerators, which provide a way to obtain mechanical energy from the environment and to collect and transmit tiny amounts of energy, has attracted a lot of attention. MOFs, because of their diverse structures as well as stable pores and large specific surface area, have very significant advantages to be used as nanogenerator materials. In this paper, two MOFs with similar spatial structures are designed to take advantage of the different coordination numbers of carboxylic acids to achieve the regulation of their microstructures.

Fluorinated covalent organic frameworks for efficient drug delivery.

In this study, two novel fluorine-functionalized crystalline covalent organic frameworks (COFs), namely DF-TAPB-COF and DF-TATB-COF, were synthesized, and their ordered structure, porosity, suitable pore size, and abundant fluorine groups were expected to serve as effective carriers in drug delivery. The excellent cell viability of DF-TAPB-COF and DF-TATB-COF was verified using MTT assays. Both COFs exhibited very high loading capacities in terms of drug loading performance, in particular the drug loading rate of DF-TAPB-COF for 5-fluorouracil (5-FU) was up to 69%.

Directed molecular structure design of coordination polymers with different ligands for regulating output performance of triboelectric nanogenerators.

A triboelectric nanogenerator (TENG) provides an effective method to harvest mechanical energy from the environment. The morphology and structure of frictional electrode materials of this type of device affect the output performance significantly. Metal-organic coordination polymers (CPs) with special structure advantages offer a vast pool of materials enabling high performances.

Fluorescent porous organic polymers for detection and adsorption of nitroaromatic compounds.

A fluorescent porous organic polymer (FPOP) with strong fluorescence and tunable emission colors, was synthesized through a simple cost-effective method via Scholl coupling reaction. Experiments proved the stability and excellent detection and adsorption ability, and microporous nature of the material. Luminescence of FPOP was quenched when addition of nitroaromatic compounds.

A novel AIE-active imidazolium macrocyclic ratiometric fluorescence sensor for pyrophosphate anion.

An imidazolium bridged macrocyclophane was synthesized as a ratiometric fluorescence sensor with aggregation-induced emission (AIE) characteristic to detect pyrophosphate anion with high selectivity among various anions. In the presence of zinc ion, macrocyclophane can form aggregates through complexation with pyrophosphate anion and emit ratiometric fluorescence, resulting from an enhancement in its aggregate-state emission and a reduction in its monomer emission. This AIE-active macrocycle showed great potential as a ratiometric fluorescence receptor.

Single-Atom and Dual-Atom Electrocatalysts Derived from Metal Organic Frameworks: Current Progress and Perspectives.

Single-atom catalysts (SACs) have attracted increasing research interests owing to their unique electronic structures, quantum size effects and maximum utilization rate of atoms. Metal organic frameworks (MOFs) are good candidates to prepare SACs owing to the atomically dispersed metal nodes in MOFs and abundant N and C species to stabilize the single atoms. In addition, the distance of adjacent metal atoms can be turned by adjusting the size of ligands and adding volatile metal centers to promote the formation of isolated metal atoms.

Hydrangea-like α-NiCo(OH) Reinforced by Ethyl Carbamate "Rivet" for All-Solid-State Supercapacitors with Outstanding Comprehensive Performance.

Improving the self-conductivity and structural stability of electrode materials is a key strategy to improve the energy density, rate performance, and cycle life of supercapacitors. Controlled intercalation of ethyl carbamate (CHCHOCONH) as the rivet between Ni-Co hydroxide layers can be used to obtain sufficient ion transport channels and robust structural stability of hydrangea-like α-NiCo(OH) (NC). Combining the improved electronic conductivity offered by the coexistence of Ni and Co optimizing itself electronic conductivity and the addition of carbon nanotubes (CNTs) as the electron transport bridge between the active material and the current collector and the large specific surface area (296 m g) reducing the concentration polarization, the capacitance retention ratio of NC-CNT from 0.

Macrocycles and cages based on tetraphenylethylene with aggregation-induced emission effect.

Organic molecules with an aggregation-induced emission (AIE) effect have recently been attracting more and more attention due to their colossal potential in solid emitters and chemo/biosensors. The number and variety of AIEgen compounds are expanding very rapidly to obtain better application performance and a wider area of application. Among AIEgen systems, tetraphenylethylene (TPE) and its derivatives are the class that have received the most extensive study and the most rapid development because of their facile synthesis.

Porous Interdigitation Molecular Cage from Tetraphenylethylene Trimeric Macrocycles That Showed Highly Selective Adsorption of CO and TNT Vapor in Air.

A new [3 + 3] trimeric macrocycle, based on tetraphenylethylene having an aggregation-induced emission effect, could form a interdigitation molecular cage with a big void by host-guest interactions. The cage could accommodate two TNT molecules and detect TNT at the 1.7 fg level per mL of air.

Evidence for Aggregation-Induced Emission from Free Rotation Restriction of Double Bond at Excited State.

This paper reports that cis-TPE dicycles emit strong fluorescence, while the gem dicycles show almost no emission in solution, demonstrating that the free rotation restriction of the double bond at the excited state is the key factor for AIE effects.

Tetraphenylethylene Foldamers with Double Hairpin-Turn Linkers, TNT-Binding Mode and Detection of Highly Diluted TNT Vapor.

Tetraphenylethylene (TPE) foldamers with double hairpin-turn linkers showing an aggregation-induced emission (AIE) effect have been synthesized for the first time. A crystal structure of a foldamer-TNT complex has been obtained, enabling unprecedented direct observation of the interactions between TNT molecules and the chromophores of the foldamer. Instead of π-π stacking interactions, which have often been considered to be the key mechanism in the binding of TNT by chromophoric receptors, strong n-π interactions between the nitro groups of TNT and the aromatic rings of the foldamer have been found.

The Fixed Propeller-Like Conformation of Tetraphenylethylene that Reveals Aggregation-Induced Emission Effect, Chiral Recognition, and Enhanced Chiroptical Property.

The propeller-like conformation of tetraphenylethylene (TPE) with aggregation-induced emission (AIE) effect was partially and completely fixed by intramolecular cyclization for the first time. The immobilization of propeller-like conformation was found to show great advantages in determining the enantiomer purity, identifying the chiral amines. The completely fixed conformers are resolved into M- and P-enantiomer, which showed mirror imaged CD and almost quantitative fluorescence quantum yield.

Enantioselective Recognition for Many Different Kinds of Chiral Guests by One Chiral Receptor Based on Tetraphenylethylene Cyclohexylbisurea.

A neutral chiral receptor based on TPE cyclohexylbisurea was synthesized and could discriminate the enantiomers of many different kinds of chiral reagents, including chiral acidic compounds, basic compounds, amino acids, and even neutral alcohols. The (1)H NMR spectra disclosed that the ability of chiral recognition could be ascribed to the multiple hydrogen bonds and CH-π interactions between the TPE urea receptor and the enantiomer of the chiral guest, which led to the selective aggregation of the receptor with one of the two enantiomers. This result exhibited a great potential in enantiomer discernment and high-throughput analysis of enantiomer composition of these chiral analytes by one chiral AIE molecule.