A solid-phase synthetic method for 3,4-dihydro-1H-2,1-benzothiazin-4-one 2,2-dioxide derivatives

Utilizing polymer-bound anthranilic acid derivatives, we were able to obtain 3,4-dihydro-1H-2,1-benzothiazine-4-one 2,2-dioxide derivatives through N-methanesulfonylation by use of sulfonyl chloride, sulfonic acid, or sodium sulfonate, N-alkylation under Mitsunobu condition, and the cyclative cleavage in 8-52% five-step overall isolated yields and 91-99% purities from Wang resin. The reactions on solid phase were monitored by on-bead ATR-FTIR spectroscopic method and checked by help of solution-phase model experiments.     

A novel amidepyridinium-based tripodal fluorescent chemosensor for phosphate ion via binding-induced excimer formation

A new tripodal fluorescent chemosensor 1 having amidepyridinium moiety as the key binding site and anthracene moiety as the sensing subunit was synthesized. In competitive polar organic solvent, this chemosensor 1 displayed high selectivity toward by formation of binding-induced excimer emission.     

A facile and simple method for the preparation of copoly(TEAMPS/VP)/silver nanocomposites for the humidity-sensing membranes

We developed a simple method for the preparation of polyelectrolyte/silver nanocomposites, where silver nanoparticles were dispersed in a polyelectrolyte. Copoly(TEAMPS/VP)/silver (w/w=100/0, 100/1, 100/2, 100/3 and 100/4) nanocomposites were obtained by a thermal decomposition reaction of silver carbamate complex at 130 degrees C, and well-dispersed silver colloids were stabilized by copolymer of tetraethylammonium 2-acrylamido-2-methyl-1-propanesulfonate (TEAMPS) and N-vinylpyrrolidone (VP). A dark brown solution in its UV-vis absorption spectrum showed surface plasmon resonance absorption bands at 420 nm in solution. The silver precursor and the resulting polyelectrolyte/Ag nanocomposite was characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), infrared (IR), transmission electron microscopy (TEM). In addition the humidity-sensing properties using copoly(TEAMPS/VP)/Ag nanocomposite films were examined.     

Thermosensitive hard spheres

We demonstrate an extension of a UV-Vis spectroscopy method to determine the phase boundaries for thermosensitive colloids as an alternative to the time-consuming sedimentation method. The Bragg attenuation peak from colloidal crystallites was monitored during the quasi-equilibrium colloidal crystal melting. The melting and freezing boundaries of the coexistence region were determined via a blue shift of Bragg's peak and the disappearance of peak area. We confirm this method using poly(N-isopropylacrylamide) (PNIPAM) particles at different charge densities and temperatures far below the lower critical solution temperature. At low pH, the particles behave as thermosensitive hard spheres.     

Inside Cover: Acid-catalyzed Disulfide-mediated Reversible Polymerization for Recyclable Dynamic Covalent Materials (Angew. Chem. Int. Ed. 11/2023)

Poly(1,2-dithiolane)s are a family of intrinsically recyclable polymers due to their dynamic covalent disulfide linkages. Despite the common use of thiolate-initiated anionic ring-opening polymerization (ROP) under basic condition, cationic ROP is still not exploited. Here we report that disulfide bond can act as a proton acceptor, being protonated by acids to form sulfonium cations, which can efficiently initiate the ROP of 1,2-dithiolanes and result in high-molecular-weight (over 1000 kDa) poly(disulfide)s. The reaction can be triggered by adding catalytic amounts of acids and non-coordinating anion salts, and completed in few minutes at room temperature. The acidic conditions allow the applicability for acidic monomers. Importantly, the reaction condition can be under open air without inert protection, enabling the nearly quantitative chemical recycling from bulk materials to original monomers.     

A Robust Metal-Organic Framework with Scalable Synthesis and Optimal Adsorption and Desorption for Energy-Efficient Ethylene Purification

Adsorptive separation is an energy-efficient alternative, but its advancement has been hindered by the challenge of industrially potential adsorbents development. Herein, a novel ultra-microporous metal-organic framework ZU-901 is designed that satisfies the basic criteria raised by ethylene/ethane (C₂H₄/C₂H₆) pressure swing adsorption (PSA). ZU-901 exhibits an “S” shaped C₂H₄ curve with high sorbent selection parameter (65) and could be mildly regenerated. Through green aqueous-phase synthesis, ZU-901 is easily scalable with 99 % yield, and it is stable in water, acid, basic solutions and cycling breakthrough experiments. Polymer-grade C₂H₄ (99.51 %) could be obtained via a simulating two-bed PSA process, and the corresponding energy consumption is only 1/10 of that of simulating cryogenic distillation. Our work has demonstrated the great potential of pore engineering in designing porous materials with desired adsorption and desorption behavior to implement an efficient PSA process.     

Peripherally Heavy-Atom-Decorated Strategy Towards High-Performance Pure Green Electroluminescence with External Quantum Efficiency over 40 %

Heavy-atom integration into thermally activated delayed fluorescence (TADF) molecule could significantly promote the reverse intersystem crossing (RISC) process. However, simultaneously achieving high efficiency, small roll-off, narrowband emission and good operational lifetime remains a big challenge for the corresponding organic light-emitting diodes (OLEDs). Herein, we report a pure green multi-resonance TADF molecule BN-STO by introducing a peripheral heavy atom selenium onto the parent BN-Cz molecule. The organic light-emitting diode device based on BN-STO exhibited state-of-the-art performance with a maximum external quantum efficiency (EQE) of 40.1 %, power efficiency (PE) of 176.9 lm W⁻¹, well-suppressed efficiency roll-off and pure green gamut. This work reveals a feasible strategy to reach a balance between fast RISC process and narrow full width at half maximum (FWHM) of MR-TADF by heavy atom effect.     

Determination and dynamics of difenoconazole residues in Chinese cabbage and soil

An analytical method was developed using a solid phase extraction （SPE） cleanup and gas chromatography for detecting the residues of difenoconazole in Chinese cabbage and soil. The recovery and the relative standard deviation of this method in Chinese cabbage was 87.6-99.0%, 1.71-10.50%, respectively; in soil was 92.4-95.5%, 4.93-10.70%, respectively. Further degradation of difenoconazole residue in Chinese cabbage and soil was studied to evaluate residue behavior and environmental safety of difenoconazole. Degradation rate of difenoconazole in both Chinese cabbage and soil followed the first order kinetics with the half-lives of 6.6-7.8 and 54.2-55.0 days, respectively.     

Fabrication and biocompatible characterization of magnetic hollow capsules

Monodispersed Fe3O4/polypyrrole （PPy） hollow particles were synthesized via controllable in-situ deposition and polymerization techniques using poly（styrene-co-acrylic） （PSA） latex as template. Field-dependent magnetization plot illustrates that the capsules are superparamagnetic at 300 K. FTIR spectrum confirms that the myoglobin （Mb） molecule adsorbed on the surface of Fe3O4/PPy hollow particle essentially retains its native structure. Furthermore, direct electrochemistry of Mb can be realized on Fe3O4/PPy capsules modified pyrolytic graphite disk electrode, which indicates that the magnetic conductive polymer capsules can promote the electron transfer of protein.     

A pure blue light emitting binaphthyl derivative：Synthesis and properties

A binaphthyl derivative with pyrene on 3 and 3＇ positions was synthesized and characterized via Suzuki coupling reaction. Emission maximum in solution was located at 390 nm with a quantum efficiency of 68% by taking 9,10-diphenyl anthracene as reference,while it is shifted to 450 nm with FWHM of 104 nm resulting from aggregation state in solid film.Glass transition temperature（Tg）and decomposition temperature were measured to be 184 and 447℃,respectively,by DSC and TGA.Unlike its photoluminescence spectrum,electroluminescent spectrum peaked at about 460 nm and shows a FWHM of 69 nm corresponding to a pure blue emission.The turn-on voltage,luminance and efficiency maximum were 5 V,2953 cd/m^2 and 1.37cd/A with CIE color coordinate of（0.16,0.15）,in the device structure of ITO/NPB（40nm）/PY-BN-PY（15nm）/BPhen（40nm）/Mg：Ag.