Tandem Rh(ii)-catalyzed 1,3-acyloxy migration/intermolecular [2 + 2] cycloaddition of electron-deficient propargylic esters with alkenes and alkynes.

Transition metal-catalyzed 1,3-acyloxy migration of propargylic esters represents one of the most straightforward routes to access allene intermediates, which could engage in various fascinating subsequent transformations. However, this process is often limited to propargylic esters with electron-donating groups due to intrinsic electronic bias, and the subsequent intermolecular reactions are quite limited. Herein, we disclosed an unprecedented Rh(ii)-catalyzed 1,3-acyloxy migration of electron-deficient propargylic esters, followed by intermolecular [2 + 2] cycloaddition with readily available alkenes and alkynes, and a large array of valuable alkylidenecyclobutane/ene scaffolds could be obtained facilely in one pot.

MXene/sPS nanocomposites: rheological, electrical conductivity, polymorphism, mechanical, thermal, and flammability properties.

MXenes as an emerging class of 2D materials have great potential in fabricating functional polymer nanocomposites. In this study, TiCT MXene as a representative MXene filler was employed to prepare sPS nanocomposites. The abundant surface groups (mainly -OH) on MXene allowed facile modification, and thus MXene nanosheets bearing -CH groups were prepared using dodecyl triethoxysiloxane (DCTES) as a modifier.

Turn-on mode probe based on the sustainable xanthohumol extract for the efficient viscosity response in a liquid system.

Viscosity is a typical physical parameter and plays an important role in nutrient transferring, diffusion process regulating and safety warning. Aberrant mitochondrial viscosity is closely associated with an imbalance in a liquid system. Nevertheless, there is currently a lack of convenient and efficient tools for the mutation of viscosity detection at the molecular level.

Azole reagents enabled ligation of peptide acyl pyrazoles for chemical protein synthesis.

Native chemical ligation (NCL) has been playing an increasingly important role in chemical protein synthesis (CPS). More efficient ligation methods that circumvent the requirement of a peptidyl thioester and thiol additive-which allow the following desulfurization or refolding in one pot-are urgently needed for the synthesis of more complex protein targets and in large quantities. Herein, we discover that the weak acyl donor peptidyl -acyl pyrazole can be activated by azole reagents like 3-methylpyrazole or imidazole to facilitate its ligation directly with an N-terminal cysteine peptide.

Caffeic acid, a natural extract, as an activatable molecular probe for viscosity detection in a liquid system.

Liquids, functioning as nutrients and energy systems, regulate various functions during storage programs. Microenvironmental viscosity is one of the most important physical parameters associated with the extent of deterioration, and it is crucial to monitor the mutation of viscosity at a molecular level. Herein, we utilized caffeic acid (CaC), a natural product extracted from thistles, as a molecular probe for viscosity sensing.

Acid-base responsive multifunctional poly(formyl sulfide)s through a facile catalyst-free click polymerization of aldehyde-activated internal diynes and dithiols.

Acid-base equilibria play a critical role in biological processes and environmental systems. The development of innovative fluorescent polymeric materials to monitor acid-base equilibria is highly desirable. Herein, a novel catalyst-free click polymerization of aldehyde-activated internal diynes and dithiols was established, and exclusively Markovnikov poly(formyl sulfide)s (PFSs) with high molecular weights and moderate stereoregularity were produced in high yields.

Preparation of reversible cross-linked amphiphilic polymeric micelles with pH-responsive behavior for smart drug delivery.

A new type of reversible cross-linked and pH-responsive polymeric micelle (PM), poly[polyethylene glycol methacrylate--2-(acetoacetoxy)ethyl methacrylate]--poly [2-(dimethylamino)ethyl methacrylate] [P(PEGMA--AEMA)--PDMAEMA], was synthesized for targeted delivery of curcumin. After reversible cross-linking of the micellar shell, the PMs with a typical core-shell structure exhibited excellent stability against extensive dilution and good reversibility of pH-responsiveness in solutions with different pH values. P(PEGMA--AEMA)--PDMAEMA has the lowest critical micelle concentration (CMC) value (0.

Exploring the supramolecular chemistry of cyclopropeniums: halogen-bonding-induced electrostatic assembly of polymers.

Exploring new noncovalent synthons for supramolecular assembly is essential for material innovation. Accordingly, we herein report a unique type of cyclopropenium-based supramolecular motif and demonstrate its applications to polymer self-assembly. Because of the "ion pair strain" effect, trisaminocyclopropenium iodides complex strongly with fluoroiodobenzene derivatives, forming stable adducts.

Boosting the zinc storage of a small-molecule organic cathode by a desalinization strategy.

Organic materials offer great potential as electrodes for batteries due to their high theoretical capacity, flexible structural design, and easily accessible materials. However, one significant drawback of organic electrode materials is their tendency to dissolve in the electrolyte. Resazurin sodium salt (RSS) has demonstrated remarkable charge/discharge performance characterized by a voltage plateau and high capacity when utilized as a cathode in aqueous zinc-ion batteries (AZIBs).

β-FeOOH/TiO/cellulose nanocomposite aerogel as a novel heterogeneous photocatalyst for highly efficient photo-Fenton degradation.

The photo-Fenton reaction provides an effective strategy for the removal of organic pollution in water environments. However, it remains a great challenge to develop photo-Fenton catalysts with high photocatalytic activity, low catalyst losses and excellent recyclability. In this work, a β-FeOOH/TiO/cellulose nanocomposite aerogel was fabricated as an efficient and convenient heterogeneous catalyst in the photo-Fenton system synthesis of TiO and β-FeOOH NPs on a cellulose-based aerogel.

Chemical energy assisted self-assembling of a porphyrin-substituted benzoic acid in complex environments.

Energy input plays a crucial role in the assembling of matter. In our present study, we utilize EDC as a chemical fuel to drive the molecular assembling of POR-COOH. POR-COOH will react with EDC to generate the intermediate POR-COOEDC first, which was well-solvated by solvent molecules.

Magnetic properties and rare earth element diffusion behavior of hot-deformed nanocrystalline dual-main-phase Nd-Ce-Fe-B magnets.

To inhibit the magnetic dilution effect of Ce in Nd-Ce-Fe-B magnets, a dual-alloy method is employed to prepare hot-deformed dual-main-phase (DMP) magnets using mixed nanocrystalline Nd-Fe-B and Ce-Fe-B powders. A REFe (1 : 2, where RE is a rare earth element) phase can only be detected when the Ce-Fe-B content exceeds 30 wt%. The lattice parameters of the REFeB (2 : 14 : 1) phase exhibit non-linear variation with the increasing Ce-Fe-B content due to the mixed valence states of Ce ions.

Isomeric thermally activated delayed fluorescence emitters for highly efficient organic light-emitting diodes.

The isomeric strategy is an important design concept in molecular design that has a non-negligible influence on molecular properties. Herein, two isomeric thermally activated delayed fluorescence (TADF) emitters (NTPZ and TNPZ) are constructed with the same skeleton consisting of an electron donor and electron acceptor but different connection sites. Systematic investigations show that NTPZ exhibits a small energy gap, large up-conversion efficiency, low non-radiative decay, and high photoluminescence quantum yield.

Catalyst-free synthesis of diverse fluorescent polyoxadiazoles for the facile formation and morphology visualization of microporous films and cell imaging.

The development of facile polymerizations toward functional heterocyclic polymers is of great significance for chemistry and materials science. As an important class of heterocyclic polymers, polyoxadiazoles (PODs) have found applications in various fields. However, the synthetic difficulties of PODs greatly restrict their structural diversity and property investigation.

Effect of organic solvents on calcium minodronate crystal morphology in aqueous solution: an experimental and theoretical study.

The influence of nine organic solvents on the crystal morphology of calcium minodronate (Ca(Min)) was investigated by experimental investigations and molecular simulations. Hirshfeld analysis was used to reveal the intermolecular interactions, and the modified attachment energy (AE) model was applied to constructing the Ca(Min)-organic-water model in different organic-water solvents. The surface structure and the mass density profile were demonstrated and analyzed.

Electrochemical behaviour of cellulose/reduced graphene oxide/carbon fiber paper electrodes towards the highly sensitive detection of amitrole.

Amitrole is a non-selective triazole herbicide that is widespread used to control a variety of weeds in agriculture, but it may pollute the environment and do harm to organisms. Thus, it is of critical significance to enlist a low-cost, sensitive, stable and renewable method to detect amitrole. In this paper, electrochemical experiments were carried out using carbon fibers/reduced graphene oxide/cellulose paper electrodes, which demonstrated good electrocatalytic performance for amitrole detection.

Super-resolved dynamics of isolated zinc formation during extremely fast electrochemical deposition/dissolution processes.

The development of zinc-air batteries with high-rate capability and long lifespan is critically important for their practical use, especially in smart grid and electric vehicle application. The formation of isolated zinc (i-Zn) on the zinc anode surface, however, could easily lead to deteriorated performance, such as rapid capacity decay. In particular, under the fast charging/discharging conditions, the electrochemical activities on the anode surface are complicated and severely suppressed.

Facile synthesis of isoquinolines and isoquinoline -oxides a copper-catalyzed intramolecular cyclization in water.

A highly efficient method for the facile access of isoquinolines and isoquinoline -oxides a Cu(i)-catalyzed intramolecular cyclization of ()-2-alkynylaryl oxime derivatives in water has been developed. This protocol was performed under simple and mild conditions without organic solvent, additives or ligands. By switching on/off a hydroxyl protecting group of oximes, the selective N-O/O-H cleavage could be triggered, delivering a series of isoquinolines and isoquinoline -oxides, respectively, in moderate to high yields with good functional group tolerance and high atom economy.

Promoting halogen-bonding catalyzed living radical polymerization through ion-pair strain.

Discovering efficient catalysts is highly desired in expanding the application of halogen-bonding catalysis. We herein report our findings on applying triaminocyclopropenium (TAC) iodides as highly potent catalysts for halogen-bonding catalyzed living radical polymerization. Promoted by the unique effect of ion-pair strain between the TAC cation and the iodide anion, the TAC iodides showed high catalytic efficiency in the halogen-bonding catalysis toward radical generation, and surpassed the previously reported organic iodide catalysts.

Dimerization of sub-nanoscale molecular clusters affords broadly tuneable viscoelasticity above the glass transition temperature.

Materials with promising mechanical performance generally demonstrate requirements for the critical sizes of their key building units, entanglements and crystal grains. Herein, only with van der Waals interaction, viscoelasticity with broad tunability has been facilely achieved below the critical size limits: the dimers of ∼1 nm polyhedral oligomeric silsesquioxane (POSS) with < 4 kD and size < 5 nm, which demonstrate distinct material physics compared to that of polymer nanocomposites of POSS. The dimeric POSSs are confirmed by scattering and calorimetrical measurements to be intrinsic glassy materials with glass transition temperatures ( s) lower than room temperature.

Recent progress in cellulose-based electrospun nanofibers as multifunctional materials.

Cellulose, the most abundant natural polymer, has good biocompatibility, biodegradability, and non-toxicity, which make it and its derivatives promising candidates for the fabrication of multifunctional materials, while maintaining sustainability and environmental friendliness. The combination of electrospinning technology and cellulose (and its derivatives) provides a feasible approach to produce nanostructured porous materials with promising functionalities, flexibility, renewability and biodegradability. At the same time, it enables value-added applications of cellulose and its derivatives that are derived from nature or even biomass waste.

Comprehending radicals, diradicals and their bondings in aggregates of imide-fused polycyclic aromatic hydrocarbons.

Quantum effects such as ferromagnetism were regarded as rare in organic materials. When reduced to radical states, imide-fused polycyclic aromatic hydrocarbons (IPAHs) have shown room-temperature ferromagnetism in our recent work, to be a potential candidate as ferromagnetic semiconductor. Here, we use variational Davydov ansatz parametrized by density functional theory to investigate the structural and optical properties of IPAHs and their radicals at both molecule and aggregate levels.

Engineering living cells with cucurbit[7]uril-based supramolecular polymer chemistry: from cell surface engineering to manipulation of subcellular organelles.

Supramolecular polymer chemistry, which closely integrates noncovalent interactions with polymeric structures, is a promising toolbox for living cell engineering. Here, we report our recent progress in exploring the applications of cucurbit[7]uril (CB[7])-based supramolecular polymer chemistry for engineering living cells. First, a modular polymer-analogous approach was established to prepare multifunctional polymers that contain CB[7]-based supramolecular recognition motifs.

Rationally designed Ru(ii)-metallacycle chemo-phototheranostic that emits beyond 1000 nm.

Ruthenium complexes are emerging as potential complements to platinum drugs. They also show promise as photo-diagnostic and therapeutic agents. However, most ruthenium species studied to date as potential drugs are characterized by short excitation/emission wavelengths.