Exploring the molecular design principles for efficient diarylethene photoacid and photohydride generators based on the photochemical reaction mechanism.

Photoacid generators (PAGs) and photohydride generators (PHGs) are specific photolabile protecting groups that release acid and hydride, respectively. Over the past decade, great efforts have been devoted to developing novel PAGs and PHGs with advanced efficiency, among which, two of the promising candidates are diarylethene (DAE)-based PAGs and PHGs, which release acids/hydrides during photochromic electrocyclization. The release quantum yield for PAGs is acceptable, while that of PHGs is only 4.

Three in one: engineering MOF channels coordinated water arrays for regulated separation of alkanes and alkenes.

Purifying alkenes (mainly ethylene and propylene) by removing their corresponding alkanes is crucial yet challenging in the chemical industry. Selective physisorption shows promise for effective separation but demands precise pore dimensions and/or pore chemistry of adsorbents. We report an yttrium-based metal-organic framework, Y(TCHB)(OH)·2HO (HIAM-317, TCHB = 3,3',5,5'-tetrakis(4-carboxyphenyl)-2,2',4,4',6,6'-hexamethyl-1,1'-biphenyl), that can separate ethylene/ethane and propylene/propane mechanisms regulated by coordinated water arrays.

Fabrication of monodisperse micron-sized and aldehyde-functionalized microspheres coating with covalent organic framework for efficient and rapid removal of copper ions from wastewater.

Covalent organic frameworks (COFs) possess an excellent ability for absorbing heavy metals, but their uneven particle size, difficult separation, and poor dispersion limit their wide application in the treatment of heavy metal pollution. In this paper, a monodisperse poly(4-allyloxybenzaldehyde--divinylbenzene) microsphere (denoted as PAD) was prepared with 4-allyloxybenzaldehyde as a functional monomer and divinylbenzene (DVB) as a crosslinker by one-step seed swelling polymerization. Subsequently, oxalyldihydrazide (ODH) and 2,4,6-trihydroxybenzene-1,3,5-tricarbaldehyde (Tp) were chosen as the precursors for coating the COF layer onto the surface of PAD through a one-pot method.

Highly dispersed noble metal nanoparticle composites on biomass-derived carbon-based carriers: synthesis, characterization, and catalytic applications.

Precious metal nanoparticles have been widely investigated due to their excellent activity shown in catalysis and sensing. However, how to prepare highly dispersed noble metal nanoparticles to improve the lifetime of catalysts and reduce the cost is still an urgent problem to be solved. In this study, a carbon-based carrier material was prepared by an expansion method and loaded with Pd or Ag nanoparticles on this carbon material to synthesize precious metal nanoparticle composites, which were characterized in detail.

Rapid quantitative analysis of petroleum coke properties by laser-induced breakdown spectroscopy combined with random forest based on a variable selection strategy.

Driven by the "double carbon" strategy, petroleum coke short-term demand is growing rapidly as a negative electrode material for artificial graphite. The analysis of petroleum coke physicochemical properties has always been an important part of its research, encompassing significant indicators such as ash content, volatile matter and calorific value. A strategy based on laser-induced breakdown spectroscopy (LIBS) in combination with chemometrics is proposed to realize the rapid and accurate quantification of the above properties.

Synthetic exploration of electrophilic xanthylation powerful -xanthylphthalimides.

Organic xanthates are broadly applied as synthetic intermediates and bioactive molecules in synthetic chemistry. Electrophilic xanthylation represents a promising approach but has rarely been explored mainly due to the lack of powerful electrophilic reagents. Herein, synthetic exploration of electrophilic xanthylation powerful -xanthylphthalimides was investigated.

Simple fabrication of carbon quantum dots and activated carbon from waste wolfberry stems for detection and adsorption of copper ion.

Removal of heavy metal pollution is an endless topic, because heavy metals can cause irreversible damage to the human body and environment. It is urgent to develop novel materials for detection and adsorption of heavy metal ions. In this paper, waste wolfberry straw was utilized as a carbon source, and two simple methods were developed to successfully prepare activated carbon (AC) and carbon quantum dots (CQDs).

Rapid quantitative analysis of rare earth elements Lu and Y in rare earth ores by laser induced breakdown spectroscopy combined with iPLS-VIP and partial least squares.

Rare earth ores are complex in composition and diverse in mineral composition, requiring high technical requirements for the selection of rare earth ores. It is of great significance to explore the on-site rapid detection and analysis methods of rare earth elements in rare earth ores. Laser induced breakdown spectroscopy (LIBS) is an important tool to detect rare earth ores, which can be used for analyses without complicated sample preparation.

Quantitative analysis of phenanthrene in soil by fluorescence spectroscopy coupled with the CARS-PLS model.

Polycyclic aromatic hydrocarbons (PAHs) are typical organic pollutants in soil and are teratogenic and carcinogenic. Therefore, rapid and accurate analysis of PAHs in soil can provide a theoretical basis and data support for soil contamination risk assessment. In this work, a fluorescence spectroscopy technique combined with partial least squares (PLS) was proposed for rapid quantitative analysis of phenanthrene (PHE) in soil.

Highly sensitive ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry detection method for levoglucosan based on Na enhancing its ionization efficiency.

The sensitive determination of levoglucosan in aqueous samples has great significance for the study of biomass burning. Although some sensitive high-performance liquid chromatography/mass spectrometry (HPLC/MS) detection methods have been developed for levoglucosan, there are still plenty of shortcomings, such as complicated sample pre-treatment procedures, large-amount sample requirements, and poor reproducibility. Herein, a new method for the determination of levoglucosan in the aqueous sample was developed using ultra-performance liquid chromatography with triple quadrupole mass spectrometry (UPLC-MS/MS).

Dative B←N bonds based crystalline organic framework with permanent porosity for acetylene storage and separation.

The utilization of dative B←N bonds for the creation of crystalline organic framework (BNOF) has increasingly received intensive interest; however, the shortage of permanent porosity is an obstacle that must be overcome to guarantee their application as porous materials. Here, we report the first microporous crystalline framework, BNOF-1, that is assembled through sole monomers, which can be scalably synthesized by the cheap 4-pyridine boronic acid. The 2D networks of BNOF-1 were stacked in parallel to generate a highly porous supramolecular open framework, which possessed not only the highest BET surface area of 1345 m g amongst all of the BNOFs but also features a record-high uptake of CH and CO in covalent organic framework (COF) materials to date.

Core-shell structured CoO@PPy composite for electrochemical determination of terbutylhydroquinone.

TBHQ is a significant synthetic antioxidant, but excessive use of TBHQ is harmful to human health. Therefore, the preparation of a high-efficiency TBHQ electrochemical sensor is of great significance. In this work, a core-shell structured CoO@PPy composite is synthesized for TBHQ determination and exhibits remarkable electrochemical properties.

A senolysis-based theragnostic prodrug strategy towards chronic renal failure.

Selective elimination of senescent cells (senolysis) has become a promising therapeutic strategy for the management of chronic renal failure (CRF), but the senolytic molecular pathways towards CRF therapy are limited. Here, we present for the first time a senescence-associated β-galactosidase (SA-β-gal) activatable theragnostic prodrug strategy to pertinently and effectively treat CRF in mice with the aid of fluorescence-guided senolysis. The signs of premature senescence, including the overexpression of β-gal, have been found in kidneys of mice with CRF, making this enzyme particularly suitable as a trigger of prodrugs for CRF therapy.

Facile fabrication of hollow tubular covalent organic frameworks using decomposable monomer as building block.

In this study, a commercial and low-toxicity hydrazide-containing building block has been used to construct azine-linked covalent organic frameworks (COFs). New style COFs were constructed between flexible formic hydrazide (FH) and 1,3,5-triformylphloroglucinal (Tp) or 1,3,5-triformylbenzene (TFB). The two resulting COFs (TpFH and TFBFH) exhibited uniform hollow tubular morphology (20-50 nm for TpFH, 50-100 nm for TFBFH).

Methyl nitrate energetic compounds based on bicyclic scaffolds of furazan-isofurazan (isoxazole): syntheses, crystal structures and detonation performances.

Two energetic bicyclic scaffolds (furazan-isoxazole and furazan-1,3,4-oxadiazole) were constructed different cyclization reactions. Based on the energetic bicyclic scaffolds, the energetic compounds, 3-(4-nitraminofurazan-3-ly)-isoxazole-5-methylnitrate 1c and 5-(4-nitraminofurazan-3-ly)-1,3,4-oxadiazole-2-methylnitrate 2c, were designed and synthesized in good yields. Because of the acidity of nitramine, the corresponding energetic ionic salts, ammonium 3-(4-nitraminofurazan-3-ly)isoxazole-5-methylnitrate 1d and ammonium 5-(4-nitraminofurazan-3-ly)-1,3,4-oxadiazole-2-methylnitrate 2e, were also obtained and well characterized, their structures were further determined by X-ray single crystal diffraction.

Surface solvation of Martian salt analogues at low relative humidities.

Salt aerosols play important roles in many processes related to atmospheric chemistry and the climate systems on both Earth and Mars. Complicated and still poorly understood processes occur on the salt surfaces when interacting with water vapor. In this study, ambient pressure X-ray photoelectron spectroscopy (APXPS) is used to characterize the surface chemical environment of Martian salt analogues originating from saline lakes and playas, as well as their responses to varying relative humidities.

Electrocatalytic reduction of protons to dihydrogen by the cobalt tetraazamacrocyclic complex [Co(NH)Cl]: mechanism and benchmarking of performances.

The cobalt tetraazamacrocyclic [Co(NH)Cl] complex is becoming a popular and versatile catalyst for the electrocatalytic evolution of hydrogen, because of its stability and superior activity in aqueous conditions. We present here a benchmarking of its performances based on the thorough analysis of cyclic voltammograms recorded under various catalytic regimes in non-aqueous conditions allowing control of the proton concentration. This allowed a detailed mechanism to be proposed with quantitative determination of the rate-constants for the various protonation steps, as well as identification of the amine function of the tetraazamacrocyclic ligand to act as a proton relay during H evolution.

Stress response decay with aging visualized using a dual-channel logic-based fluorescent probe.

Diagnosing aging for preventative intervention generally relies on the tracking of aging biomarkers in the resting state. However, the static marker levels are insufficient to fully evaluate aging, particularly given that the stress response capacity (SRC) decay is currently viewed as a critical feature of aging. Therefore, we have developed a dual-channel fluorescent probe capable of the logic-based visualization of thiophenol (stressor) and HOCl (thiophenol-activated stress response product) , which provides a new strategy from the time dimension to precisely assess the SRC of individuals under stress using the dual-channel fluorescence ratio.

Rhodium-Catalyzed Enantioselective and Desymmetrizative Pauson-Khand Reaction: Access to Tricyclo[6.2.1.0]undecenes.

Rhodium-catalyzed asymmetric desymmetrization Pauson-Khand reaction of C4-alkynyl-tethered cyclohexadienones has been developed as a novel strategy for access to fused 6-5-5 tricycles bearing three consecutive stereogenic centers. An array of chiral tricyclo[6.2.

Supramolecular-induced regiocontrol over the photochemical [4 + 4] cyclodimerization of NHC- or azole-substituted anthracenes.

Thanks to the impressive control that microenvironments within enzymes can have over substrates, many biological reactions occur with high regio- and stereoselectivity. However, comparable regio- and stereoselectivity is extremely difficult to achieve for many types of reactions, particularly photochemical cycloaddition reactions in homogeneous solutions. Here, we describe a supramolecular templating strategy that enables photochemical [4 + 4] cycloaddition of 2,6-difunctionalized anthracenes with unique regio- and stereoselectivity and reactivity using a concept known as the supramolecular approach.

First-generation species-selective chemical probes for fluorescence imaging of human senescence-associated β-galactosidase.

Human senescence-associated β-galactosidase (SA-β-gal), the most widely used biomarker of aging, is a valuable tool for assessing the extent of cell 'healthy aging' and potentially predicting the health life span of an individual. Human SA-β-gal is an endogenous lysosomal enzyme expressed from , the catalytic domain of which is very different from that of β-gal, a bacterial enzyme encoded by . However, existing chemical probes for this marker still lack the ability to distinguish human SA-β-gal from β-gal of other species, such as bacterial β-gal, which can yield false positive signals.

Two-in-one strategy for fluorene-based spirocycles Pd(0)-catalyzed spiroannulation of -iodobiaryls with bromonaphthols.

Rapid assembly of fluorene-based spirocycles represents a highly significant but challenging task in organic synthesis. Reported herein is a novel Pd(0)-catalyzed [4+1] spiroannulation of simple -iodobiaryls with bromonaphthols for the one-step construction of [4,5]-spirofluorenes in high yields with excellent functional group tolerance. Noteworthily, these valuable fluorene-based coumarin skeletons can enrich the database of -coumarins and exhibit excellent spectroscopic properties.

Time-resolved characteristics of laser induced breakdown spectroscopy on non-flat samples by single beam splitting.

A single-beam-splitting approach was used to enhance the signal intensity of LIBS under the extreme conditions of laser beam grazing of the surface of non-flat samples. Time-resolved spectra show that the laser-ablated plasma presents a stronger spectral intensity and a slower plasma decay in the split beam mode because of the higher laser irradiance. The temporal evolutions of signal enhancement factors indicate that the enhancement effect first rises and then drops with delay time and the maximum enhancement factor of Al plasma comes later than that of Cu plasma under the same laser energy.

Enhancement of the photocatalytic synchronous removal of Cr(vi) and RhB over RP-modified flower-like SnS.

Although photocatalysis is frequently employed to remove various pollutants in water, it still suffers from low efficiency due to the rapid recombination of photogenerated electrons and holes. In this study, a red phosphorus/tin disulfide (RP/SnS) composite photocatalyst is fabricated by loading nano-sized RP on flower-like SnS films with a facile hydrothermal method. It is noteworthy that the 2D heterojunction formed between SnS and RP provided channels for the rapid transfer of photon-generated carriers and their effective separation.

Programmable ROS-Mediated Cancer Therapy via Magneto-Inductions.

Reactive oxygen species (ROS), a group of oxygen derived radicals and derivatives, can induce cancer cell death via elevated oxidative stress. A spatiotemporal approach with safe and deep-tissue penetration capabilities to elevate the intracellular ROS level is highly desirable for precise cancer treatment. Here, a mechanical-thermal induction therapy (MTIT) strategy is developed for a programmable increase of ROS levels in cancer cells via assembly of magnetic nanocubes integrated with alternating magnetic fields.