We detail the generation of a pulsed atomic oxygen (AO) broad beam with a high flux-density via collision-induced dissociation of O2 to support practical industrial exploitation of AOs, particularly for facilitating 2-dimenstional oxidation/etching at a fast rate of one-monolayer per second in an area ≥1000cm2. This innovation fuses the following interdisciplinary concepts: (a) a high density of O+ can be produced in an electron-cyclotron-resonance (ECR) O2 plasma; (b) O+ can be extracted and accelerated with an aperture-electrode in the plasma; (c) O+ with adequate kinetic energy can initiate a cascade of gas-phase collisions in the presence of O2; (d) collision-induced dissociation of O2 yields AOs with adequate kinetic energy which can cause additional collision-induced dissociation of O2. Computational simulations of such collisions, with both ab initio molecular dynamics and direct simulation Monte Carlo methods, are used to guide the experimental generation of the proposed AO-beam. We experimentally demonstrate the highest known AO mean flux-density of about 1.5×1016 atoms cm-2 s-1 in a broad-beam, and use it to oxidatively modify a self-assembled molecular layer of siloxane on a silicon wafer. In addition, we also demonstrate the growth of Al2O3 through an AO-assisted atomic layer deposition process at a room temperature.

Molecular ferroelastic with the natural features of mechanical flexibility and switchable spontaneous strain have attracted widespread attention in the scientific community due to their potential applications in tunable gratings, flexible memorizers, strain sensors, and intelligent actuators. However, most designs of molecular ferroelastics remain in the stage of blind exploration, posing a challenge to achieve a functional ferroelastic more effectively. Herein, we have successfully obtained a molecular ferroelastic, [Me2NH(CH2)2NH3](ReO4)2 (Me2NH(CH2)2NH3 = N,N-dimethylethylenediammonium), under the guidance of the mono-/double-protonating strategy. The double-protonated [Me2NH(CH2)2NH3](ReO4)2 undergoes a paraelastic-ferroelastic phase transition with the Aizu notation of 2/mF-1 at 322 K. Meanwhile, the theoretical calculation and experimental measurement simultaneously show that [Me2NH(CH2)2NH3](ReO4)2 possesses good mechanical flexibility, because its elastic modulus (E) of 8.26 GPa and hardness (H) of 0.45 GPa is smaller than the average value of organic crystals (E of 12.05 GPa and H of 0.5 GPa), which makes it promising to apply in wearable pressure sensors, implantable medical sensors, high-precision tuners, etc. This work further enriches the molecular ferroelastic family and demonstrates that mono-/double-protonation is one of the effective molecular modification strategies for designing ferroelastics.

An method for the electrochemical synthesis of chalcogenosulfonates via a tandem multi-component reaction has been developed. This method is performed in an undivided cell without the requirement of external oxidants, acids, and transition metals. A variety of indoles and sulfinic acid sodium salts can be used in this method, and it is effective for the late-stage modifications of complex molecules. Not only thiosulfonates and selenosulfonates but also sulfonotelluroates could be prepared, making this protocol a useful tool for the devel-opment of new functional molecules. The afforded products are promising for pesticide development.

An efficient electrochemical approach has been developed for the construction of 3-phenylsulfanylquinoline derivatives by treating phenylethynylbenzoxazinanones with aryl disulfide in an undivided cell. The protocol provided a convenient route to functionalized quinolines with good functional group tolerance. Moreover, it does not require any metal catalysts or additives, furnishing a series of biological quinolines in moderate to good yields.

Although, great achievements have been made in the synthesis of heterocycles using radical addition/cyclization strategy, developing versatile alkyl radical precursors, especially the non-stabilized ones for this method still remains a huge challenge. Herein, we report an efficient annulation cascade reaction between cyclosulfonium salts and alkenes for the synthesis of sulfur-containing N-heterocycles by visible light/copper catalysis under mild conditions. The C−S bond cleavage/radical cascade reaction delivers a variety of corresponding N-heterocycles containing aryl alkyl thioether motifs with good functional group tolerance. Significantly, the current system could be used for the late-stage functionalization of complex bioactive molecules.

An asymmetric isomerization/intramolecular coupling reaction of allylic alcohols to synthesize chiral dihydrocoumarins was suc-cessfully accomplished through ruthenium catalysis. This method demonstrates a wide substrate applicability, excellent tolerance for various functional groups, and good enantioselectivities (up to 90% ee). It provides a convenient pathway to produce a diverse range of structurally distinct chiral dihydrocoumarins in good efficiency.

Herein, we present a method for the homogeneous hydrogenation of nitroarenes to produce aromatic amines using low catalyst loading (1 mo%) of air-stable copper N-heterocyclic carbene complexes as the catalyst and ammonia borane as the source of hydrogen. A wide range of nitroarenes, featuring diverse functional groups, were selectively transformed into their corresponding primary aromatic amines with high yields. This process can be readily scaled up and exhibits compatibility with various sensitive functional groups, including halogen, trifluoromethyl, aminomethyl, alkenyl, cyano, ester, amide, and hydroxyl. Notably, this catalytic methodology finds application in the synthesis of essential drug compounds. Mechanistic investigations suggest that the in-situ-generated Cu-H species may serve as active intermediates, with reduction pathways involving species such as azobenzene, 1,2-diphenylhydrazine, nitrosobenzene, and N-phenylhydroxylamine.

3-Idolenone is a key intermediate in the synthesis of many drugs and plays an important role in synthetic chemistry and biochemi-stry. A new method for the synthesis of trifluoromethylated 3-indolenones by carbonylation reaction catalyzed by Pd (0) is de-scribed. In the absence of an additive, 1-chloro-3,3,3-trifluoro-propylene (a cheap ozone-friendly CF3 structural unit) reacts with indole and carbon monoxide to synthesize trifluoromethylatedindolenone, good yield, Regioselectivity and Chemoselectivity, and strong resistance to basal functional groups such as alkynes, aldehydes and esters. It is worth mentioning that not only indole compounds can be well transformed into the corresponding products, pyrrole, hetero-indole also can be well completed the cor-responding chemical transformation. This late construction of trifluoromethylated indole/pyrrole 3-ketene provides a scientific method.

The development of efficient and sustainable methods to obtain spirocyclic compounds is of significance as these structures are widely found in pharmaceuticals and agrochemicals. Herein, we disclose an electrochemical dearomative spirocyclization of N-acyl sulfonamides in a continuous-flow cell. The reaction is simple and efficient without external catalysts or supporting electrolytes, in-cluding a decagram-scale synthesis.

Polymer mechanochemistry on reactive species has attracted more and more attentions over the past 20 years, as the mechanochemical generation of reactive species has a great potential in developing different polymeric materials for various proposes, such as stress detection, self-healing, self-strengthening, controllable degradation and release of small molecules. In this review, we first discuss the recent progress on polymer mechanochemistry of the reactive species that are generated from the mechanochemical reactions of mechanophores. Five types of reactive species, including radical, zwitterion, ionic, carbene and neutral intermediates, and their applications were reviewed in detail. Since mechanochemical reactions are sensitive to the mechanophore structure and polymer framework, we then discuss how mechanophore isomerism, polymer structure, polymer attachment point, and polymer architecture influence the mechanophore activation. At last, we provide our perspectives on the polymer mechanochemistry of reactive species.

A disposable monolithic column mass spectrometry kit was developed based on monolithic column for microsampling, purification, storage, transportation and direct MS analysis of whole blood. The kit mainly consists of a capillary for quantitative microsampling of very small amount of blood (2 μL), a cation exchange monolithic column for purification and storage, and a syringe for loading sample. The cost of the kit is estimated to only one dollar. This MS kit is very friendly to various users that one can easily siphon small amount blood in the kit followed by rapid sample clean-up in 30s. We established a rapid quantitative method using the kit with a limit detection as low as 0.33 nM, achieved more than five orders of magnitude enhancement in MS analysis sensitivity compared to nanoelectrospray ionization MS analysis. The kit can avoid analyte exposure to oxygen, moisture and sunlight, which helps the storage of the sample. The relative standard deviation within 10 days were less than 10%. This method has been successfully applied to the quantitative analysis of procainamide hydrochloride in 2 μL rat blood. These results indicate that this kit does have the potential to achieve low-cost, highly sensitive quantitative MS analysis of biological sample.

Stability against oxygen is an important factor affecting the performance of organic semiconductor devices. Improving photooxidation stability can prolong the service life of the device and maintain the mechanical and photoelectric properties of the device. Generally, various encapsulation methods from molecular structure to macroscopic device level are used to improve photooxidation stability. Here, we adopted a crystallization strategy to allow 14H-spiro[dibenzo[c,h]a-cridine-7,9′-uorene] (SFDBA) to pack tightly to resist fluo-rescence decay caused by oxidation. In this case, the inert group of SFDBA acts as a “steric armor”, protecting the photosensitive group from being attacked by oxygen. Therefore, compared with the fluorescence quenching of SFDBA powder under two hours of sunlight, SFDBA crystal can maintain its fluorescence emission for more than eight hours under the same conditions. Furthermore, the photolu-minescence quantum yields (PLQYs) of the crystalline film is 327.37 % higher than that of the amorphous film. It shows that the crystal-lization strategy is an effective method to resist oxidation.

An efficient and convenient method was developed for the one-pot construction of pyrrolo[1,2-a]quinoxalines via a Cu(II)-catalyzed domino reaction between 2-(1H-pyrrol-1-yl)anilines and alkylsilyl peroxides. The synthetic protocol is characterized by a broad sub-strate scope, O2 as oxidant, and commercially readily available catalysts. This reaction proceeds through a C–C bond cleavage and new C–C and C–N bond formation. A mechanistic study suggests that alkyl radical species participate in the cascade reaction.

The Pd-catalyzed dipolar cycloaddition represents a significant synthetic strategy for the construction of useful heterocyclic com-pounds. This study developed the dipolar [4+2] and [6+2] cycloaddition reactions of benzo[d]isothiazole 1,1-dioxides (BDs) leading to the synthesis of BD-fused 1,3-oxazinane and 1,3-oxazocane derivatives, respectively. In particular, the synthesis of BD-fused 1,3-oxazinanes demonstrated regio- and enantioselective characteristics, resulting in products with good yields, enantioselectivity and regioselectivity (if applicable). Furthermore, the [6+2] cycloaddition reaction developed in this work represented the first strat-egy for the synthesis of medium-sized ring compounds based on BDs.