Single-step Reaction Research Articles

An Asymmetric Coumarin-Anthracene Conjugate as Efficient Fullerene-Free Acceptor for Organic Solar Cells.

Asymmetric wide-band gap fullerene-free acceptors (FFAs) play a crucial role in organic solar cells (OSCs). Here, we designed and synthesized a simple asymmetric coumarin-anthracene conjugate named CA-CN with optical band gap of 2.1 eV in a single-step condensation reaction. Single crystal X-ray structure analysis confirms various multiple intermolecular non-covalent interactions. The molecular orbital energy levels of CA-CN estimated from cyclic voltammetry were found to be suitable for its use as an acceptor for OSCs. Binary OSCs fabricated using CA-CN as acceptor and PTB7-Th as the donor achieve a power conversion efficiency (PCE) of 11.13 %. We further demonstrate that the insertion of 20 wt % of CA-CN as a third component in ternary OSCs with PTB7-Th : DICTF as the host material achieved an impressive PCE of 14.91 %, an improvement of ~43 % compared to the PTB7-Th : DICTF binary device (10.38 %). Importantly, the ternary blend enhances the absorption coverage from 400 to 800 nm and improves the morphology of the active layer. The findings highlight the efficacy of an asymmetric design approach for FFAs, which paves the way for developing high-efficiency OSCs at low cost.

Efficient single-step mechanosynthesis route of nanostructured Hf0.2Nb0.2Ta0.2V0.2Zr0.2C0.5N0.5 High Entropy Carbonitride Powder

Nowadays high entropy carbides (HECs) are an important group of advanced ceramics. They are composed by at least by five transition metals (TMs) in nearly equiatomic proportion and disordered distributed in the cationic sublattice of face centered cubic structures, with carbon atoms in the octahedral interstitial voids, with general formula (TM1,TM2,TM3,TM4,TM5)C. These HECs belong to the recent novel group of ultra-high temperature ceramics (UHTCs), with superior properties in comparison with the constituent binary carbides. However, the synthesis of those HECs can be modified to develop high entropy carbonitrides, HECNs, where the C are partially substituted by N, to form a solid solution in the anionic sublattice, with expected improved properties as UHTCs, but they are in an incipient state of development. Here, we report the synthesis and deep characterization of a non-previously obtained Hf0.2Nb0.2Ta0.2V0.2Zr0.2C0.5N0.5 HECN, via a facile, single step and reproducible solid-gas reaction mechanosynthesis route. The synthesis was successfully completed in a planetary ball mill device, after 2h of milling time, at 400 rpm and using a ball-to- powder ratio of 60:1 in a pure N2 atmosphere at room temperature. The as-synthesized HECNs powdered showed nanostructured morphology and outstanding high-temperature oxidation resistance up to 1500 °C.

Air-Stable and Eco-Friendly Symmetrical Imine with Thiadiazole Moieties in Neutral and Protonated form for Perovskite Photovoltaics.

This paper proposes molecular and supramolecular concepts for potential application in perovskite solar cells. New air-stable symmetrical imine, with thiadiazole moieties PPL2: (5E,6E)-N2,N5-bis(4-(diphenylamino)benzylidene)-1,3,4-thiadiazole-2,5-diamine), as a hole-transporting material was synthesised in a single-step reaction, starting with commercially available and relatively inexpensive reagents, resulting in a reduction in the cost of the final product compared to Spiro-OMeTAD. Moreover, camphorsulfonic acid (CSA) in both enantiomeric forms was used to change the HOMO-LUMO levels and electric properties of the investigated imine-forming complexes. Electric, optical, thermal, and structural studies of the imine and its complexes with CSA were carried out to characterise the new material. Imine and imine/CSA complexes were also characterised in depth by the proton Nuclear Magnetic Resonance 1H NMR method. The position of nitrogen in the thidiazole ring influences the basicity of donor centres, which results in protonation in the imine bond. Simple devices of ITO/imine (with or without CSA(-) or CSA(+))/Ag/ITO architecture were constructed, and a thermographic camera was used to find the defects in the created devices. Electric behaviour was also studied to demonstrate conductivity properties under the forward current. Finally, the electrical properties of imine and its protonated form with CSA were compared with Spiro-OMeTAD. In general, the analysis of thermal images showed a very similar response of the samples to the applied potential in terms of the homogeneity of the formed organic layer. The TGA analysis showed that the investigated imine exhibits good thermal stability in air and argon atmospheres.

Hydrogels with Differentiated Hydrogen-Bonding Networks for Bioinspired Stress Response.

Stress response, an intricate and autonomously coordinated reaction in living organisms, holds a reversible, multi-path, and multi-state nature. However, existing stimuli-responsive materials often exhibit single-step and monotonous reactions due to the limited integration of structural components. Inspired by the cooperative interplay of extensor and flexor cells within Mimosa's pulvini, we present a hydrogel with differentiated hydrogen-bonding (H-bonding) networks designed to enable the biological stress response. Weak H-bonding domains resemble flexor cells, confined within a hydrophobic network stabilized by strong H-bonding clusters (acting like extensor cells). Under external force, strong H-bonding clusters are disrupted, facilitating water diffusion from the bottom layer and enabling transient expansion pressure gradient along the thickness direction. Subsequently, water diffuses upward, gradually equalizing the pressure, while weak H-bonding domains undergo cooperative elastic deformation. Consequently, the hydrogel autonomously undergoes a sequence of reversible and pluralistic motion responses, similar to Mimosa's touch-triggered stress response. Intriguingly, it exhibits stress-dependent color shifts under polarized light, highlighting its potential for applications in time-sensitive "double-lock" information encryption systems. This work achieves the coordinated stress response inspired by natural tissues using a simple hydrogel, paving the way for substantial advancements in the development of intelligent soft robots.

Boosting Zinc Hybrid Supercapacitor Performance via Thiol Functionalization of Graphene-Based Cathodes.

Zinc hybrid supercapacitors (Zn-HSCs) hold immense potential toward the next-generation energy storage systems, effectively spanning the divide between conventional lithium-ion batteries (LIBs) and supercapacitors. Unfortunately, the energy density of most of Zn-HSCs has not yet rivalled the levels observed in LIBs. The electrochemical performance of aqueous Zn-HSCs can be enhanced through the chemical functionalization of graphene-based cathode materials with thiol moieties as they will be highly suitable for favoring Zn2+ adsorption/desorption. Here, a single-step reaction is employed to synthesize thiol-functionalized reduced graphene oxide (rGOSH), incorporating both oxygen functional groups (OFGs) and thiol functionalities, as demonstrated by X-ray photoelectron spectroscopy (XPS) studies. Electrochemical analysis reveals that rGOSH cathodes exhibit a specific capacitance (540 Fg-1) and specific capacity (139 mAhg-1) at 0.1 Ag-1 as well as long-term stability, with over 92% capacitance retention after 10000 cycles, outperforming chemically reduced graphene oxide (CrGO). Notably, rGOSH electrodes displayed an exceptional maximum energy density of 187.6Whkg-1 and power density of 48.6kWkg-1. Overall, this study offers an unprecedented powerful strategy for the design and optimization of cathode materials, paving the way for efficient and sustainable energy storage solutions to meet the increasing demands of modern energy applications.

Electroreductive Remote Benzylic C(sp3)-H Arylation of Aliphatic Ethers Using Cyanoarenes for the Synthesis of α-(Hetero)aryl Ethers.

An iodoarene-driven electroreductive remote C(sp3)-H arylation of unsymmetrical 1-(o-iodoaryl)alkyl ethers with cyanoarenes for the site selective synthesis of α-(hetero)aryl ethers is developed. With the introduction of cyanoarenes as both aryl sources and electron transfer mediators, this method includes an iodoarene-driven strategy to enable the regiocontrollable formation of two new bonds, one C(sp2)-H bond, and one C(sp2)-C(sp3) bond, in a single reaction step through the sequence of halogen atom transfer (XAT), hydrogen atom transfer (HAT), radical-radical coupling, and decyanation.

Co-pyrolysis model for polylactic acid (PLA)/wood composite and its application in predicting combustion behaviors

Polylactic acid (PLA)/wood composite has gained great popularity in applications due to its renewable and biodegradable features, whereas quantitative modelling from microscale co-pyrolysis to bench-scale combustion was barely reported. To challenge this issue, poplar wood, PLA and three PLA/wood composites with mass ratios of 1:3, 1:1, and 3:1 were adopted to conduct thermogravimetric analysis (TGA) and cone calorimeter tests. A numerical model was utilized to examine the interaction between wood and PLA during co-pyrolysis. Kinetics and temperature-dependent thermodynamics of each component were determined by inversely modelling some specific experimental results, while the remaining data were used for model validation. Effective heats of combustion of gas products were estimated by fitting the recorded heat release rates (HRR) in combustion tests. The results showed that PLA/wood composites considerably reduced the peak temperature of co-pyrolysis by 21.7–23.7 K compared to neat PLA. Pyrolysis of wood and PLA could be described by a four-component reaction scheme and a single-step reaction, respectively, whereas two additional reactions were needed to quantify the interaction between PLA and wood. Three methods were used to predict the measured HRRs, and all calculated curves fitted the experimental results well. PLA/wood composites decelerated the thickness regression rate and prolonged the combustion time. Meanwhile, measured CO and CO2 production rates were thoroughly analyzed.

Copper-catalyzed photoredox 1,4-amidocyanation of 1,3-enynes with N-amidopyridin-1-ium salts and TMSCN: Facile access to α-amido allenyl nitriles

A new 1,4-amidocyanation of 1,3-enynes with N-amidopyridin-1-ium salts and TMSCN using a copper and photoredox synergetic catalysis for producing α-amido allenyl nitriles is developed. Employing N-amidopyridin-1-ium salts as the amidyl radical precursors, the reaction enables the formation of two new bonds, one C(sp3)-N bond and one C(sp2)-C(sp) bond, in a single reaction step. This reaction represents a mild, general route to the construction of the α-amido allenyl nitrile architectures, which characterizes a broad scope, a good functional group compatibility and an excellent selectivity.

The influence of supersonic spatial-temporal coupling disturbance on detonation in an expanded chamber

At present, the most researches on perturbed detonation only considers single factor effects, and there are few studies on the impact of multi-factor coupled perturbations on detonation. In order to match the complex inflow conditions in real situation, the initiation and propagation process of detonation disturbed by spatial-temporal coupling have been studied. This study adopts an adaptive mesh refinement program. It can dynamically capture the structure change of detonation and reduce the total calculation amount. The N-S (Navier-Stokes) equation and single-step reaction model was used in this study. The calculation model is the classic expansion channel that can enhance thrust. After analyze the effects of disturbance amplitudes and disturbance stratification, the results indicates that the stratification phenomenon of disturbance has different effects on the characteristics of flow field. The expansion wall can weaken the disturbance intensity, but its effect is limited. It can only achieve good results when the disturbance on the straight wall side is weak, but the weakening effect of expansion wall also exacerbates the instability of wave. On the other hand, the stability of detonation waves under spatial stratification is stronger, which helps to maintain the intensity of detonation wave.

Cobalt-Promoted Photoredox 1,2-Amidoamination of Alkenes with N-Sulfonamidopyridin-1-ium Salts and Free Amines.

A cobalt-promoted photoredox 1,2-amidoamination of alkenes with N-sulfonamidopyridin-1-ium salts and free amines for the synthesis of unsymmetrical vicinal diamines has been developed. The reaction handles N-(sulfonamido)pyridin-1-ium salts as the sulfonamidyl radical precursors and free amines as the nucleophilic terminating reagents to enable the formation of two new C(sp3)-N bonds in a single reaction step and offers a route to selectively producing unsymmetrical vicinal diamines with an exquisite selectivity and a good compatibility of functional groups.

Effect of Concentration of KOH, H2O, Temp in In-situ Transestrification Reaction of Sesbania sesban, Capparis deciduas seed

Fatty acid methyl ester is defined as the mono-alkyl esters of fatty acids derived from vegetable oils or animal fats. In simple terms, it is renewable source of energy. Petrodiesel can be replaced by biodiesel due to its superiority. Biodiesel has more lubricity which increases lifetime of engine. It is less toxic and gives less emission of Carbon dioxide, Carbon monoxide, hydrocarbons and particulate matter. The biodiesel fraction from oil content of Sesbania sesban, Capparis deciduas are found 29% & 63.75 respectively. The percentage of biodiesel yield increases with concentration of KOH as a catalyst. The aim of this article is to demonstrate the cost effective new source of energy by single step reaction i.e. production of oil by combining extraction and reaction of extract with the mixture of alcohols. In this article the effect of catalyst concentration, time, water content and temperature on in-situ transestrification is studied to obtain optimum yield of fatty acid methyl ester (Biodiesel).Fuel characterization tests show the striking similarity of various physical & chemical properties and campers to ASTM standards.

Exploring multistep bischofite waste pyrolysis: insights from advanced kinetic analysis and thermogravimetric techniques.

Pyrolysis technology is crucial for realizing waste bischofite resource utilization. However, previous studies overlooked the complexity of multistep pyrolysis, resulting in a lack of thorough knowledge of the pyrolysis behavior and kinetics. The pyrolysis products were characterized using XRD and FTIR to indicate the bischofite pyrolysis behavior. Additionally, the multistep kinetics was studied using the segmented single-step reaction (SSSR) and Fraser-Suzuki combined kinetic (FSCK) methods. The results show that the bischofite pyrolysis is divided into dehydration and hydrolysis. The former refers to removing crystalline water from MgCl2·nH2O (n = 4,6). At the same time, the latter is related to the removal of HCl, characterized by the strengthening of the Mg-O bond in the FTIR analysis and the emergence of MgOHCl·1.5H2O in the XRD examination. The two main stages are divided into three dehydration reactions (D-1, D-2, D-3) and three hydrolysis reactions (H-1, H-2, H-3) by DTG-DDTG or Fraser-Suzuki deconvolution. Compared with the SSSR method, the FSCK method has improved model repeatability for multistep kinetic parameters. Following Fraser-Suzuki deconvolution, the FSCK method creates almost the same activation energy results when using the Friedman (FR), Kissinger-Akahira-Sunose (KAS), and Vyazovkin (VZK). This work provides fundamental data to promote the maximizing waste bischofite resource utilization.

An Alternative Green Method for Synthesis of 3-Amino-5-Methylisoxazole Schiff Bases and Their Bioactivity Evaluation

Isoxazole Schiff bases play an important role in medicinal chemistry, pharmacy, coordination chemistry, and industrial chemistry, therefore, finding easier and more reliable procedures for their synthesis is still in process. The present work deals with a single-step condensation reaction between 3-amino-5-methylisoxazole and various aromatic aldehydes to furnish a Schiff base scaffold of isoxazole (including one new compound) with excellent yields in a short time. The procedure is a solvent-free condition using DMEA as a green catalyst. The products were evaluated for their antibacterial efficacy against gram-positive and gram-negative bacteria including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Salmonella abony. The antioxidant activity of the products was tested and the ascorbic acid and quercetin were used as standards. The produced Schiff bases exhibited the ability to scavenge the free radicals from the DPPH. This means that the products can be used as antioxidants. Two of the synthesized compounds were evaluated for their anticancer activity by testing their cytotoxic potency, which showed diminishing toxicity of cell lines against human breast cancer cell lines and gastric adenocarcinoma cell lines. Therefore, the products can be utilized as anticancer agents.

Cu2O-catalyzed cascade phosphinylation/cyclization of 2'-aminochalcones for the synthesis of hemi-indigo derivatives.

A Cu2O-catalyzed cascade phosphinylation/cyclization reaction of 2'-aminochalcones and diphenylphosphine oxides to produce hemi-indigo derivatives has been developed. This strategy facilitates the sequential formation of a C-P bonds and a C-N bond in a single reaction step. Notably, the approach features one-pot operation, an earth-abundant copper catalyst, readily available starting materials, a broad substrate scope and high compatibility with functional groups, providing 33 compounds in acceptable yields.

Identification of 1,2,4-triazole-bearing Bis-Schiff base hybrid scaffolds: In vitro and in silico insights to develop promising anti-urease and anti-cancer agents

The present work describes the synthetic procedure of 1,2,4-triazole derivatives (1–14) synthesized efficiently in a single step reaction. Basic skeleton confirmation was achieved through different characterization approaches, such as nuclear magnetic resonance(1HNMR and13CNMR) and high-resolution electron ionization mass spectrometry(HREI-MS). In vitro biological assessment of these scaffolds as anti-urease and anti-cancer agents was analyzed in presence of their standard compounds thiourea (IC50 = 9.30 ± 0.20 µM)and Tetrandrine (IC50 = 11.70 ± 0.10 µM), respectively. Inhibition ranges were observed for all scaffolds with IC50 = 2.10 ± 0.20–––37.40 ± 1.10 µM and IC50 = 4.10 ± 0.10–––39.90 ± 0.20 µM, respectively. Among the screened, the potent behavior were shown by scaffolds 3 (IC50 = 2.10 ± 0.20 and 4.10 ± 0.10 µM), 4(IC50 = 3.20 ± 1.10 and 5.20 ± 0.20 µM), 5(IC50 = 4.20 ± 0.30 and 5.60 ± 0.10 µM), 13(IC50 = 5.80 ± 1.10 and 5.90 ± 0.10 µM)and 14(IC50 = 4.30 ± 1.20 and 6.10 ± 1.20 µM).These analogs show the excellent inhibition owing to the spellbinding reactivity of –CF3, −F, −Cl and –OH moieties, which decelerate enzyme potential via effective binding between drug molecule and enzyme. These compounds were further investigated by means of molecular docking studies which explore the binding interaction of ligand within the binding pockets of enzymes. In this regard, excellent results were found in both the activity profiles of these scaffolds. Additionally, ADMET investigations also strengthen the drug profile of the potent compounds.

Solution and gaseous phase sensing of formaldehyde with economical triphenylmethane based sensors: a tool to estimate formaldehyde content in stored fish samples.

The use of formalin to preserve raw food items such as fish, meat, vegetables etc. is very commonly practiced in the present day. Also, formaldehyde (FA), which is the main constituent of formalin solution, is known to cause serious health issues on exposure. Considering the ill effects of formaldehyde, herein we report synthesis of highly sensitive triphenylmethane based formaldehyde (FA) sensors from a single step reaction of inexpensive reagents namely 4-hydroxy benzaldehyde and 2,6-dimethyl phenol. The synthetic method also provides highly pure product in bulk quantity. The analytical activity of the triphenylmethane sensor 1 with a limit of detection (LOD) value of 2.31 × 10-6 M for FA was significantly enhanced through induced deprotonation and thereafter a LOD value of 1.82 × 10-8 M could be achieved. To the best of our knowledge, the LOD value of the deprotonated form (sensor 2) for FA was superior to those of all the FA optical sensors reported so far. The mechanism of sensing was demonstrated by 1H-NMR titration and recording mass spectra before and after addition of FA to a solution of sensor 2. Both sensor 1 and sensor 2 exhibit quenching in emission upon addition of FA. A fluorescence study also demonstrates enhancement in analytical activity of the sensor upon induced deprotonation. Then the sensor was effectively immobilized into a hydrophilic and biocompatible starch-PVA polymer matrix which enabled detection of FA in a 100% aqueous system reversibly. Again, quick and effective sensing of FA in real food samples (stored fish) with the help of a computational application was demonstrated. The sensors have significant practical applicability as they effectively detect FA in real food samples qualitatively and quantitatively.

The mechanism of Mo-nitrogenase: from N2 capture to first release of NH3.

Mo-nitrogenase hydrogenates N2 to NH3. This report continues from the previous paper [I. Dance, Dalton Trans., 2024, 53, 14193-14211] that described how the active site FeMo-co of the enzyme is uniquely able to capture and activate N2, forming a key intermediate with Fe-bound HNNH. Density functional simulations with a 485+ atom model of the active site and its surroundings are used to describe here the further reactions of this HNNH intermediate. The first step is hydrogenation to form HNNH2 bridging Fe2 and Fe6. Then a single-step reaction breaks the N-N bond, generating an Fe2-NH-Fe6 bridge and forming NH3 bound to Fe6. Then NH3 dissociates from Fe6. Reaction potential energies and kinetic barriers for all steps are reported for the most favourable electronic states of the system. The steps that follow the Fe2-NH-Fe6 intermediate, forming and dissociating the second NH3, and regenerating the resting state of the enzyme, are outlined. These results provide an interpretation of the recent steady-state kinetics data and analysis by Harris et al., [Biochemistry, 2022, 61, 2131-2137] who found a slow step after the formation of the HNNH intermediate. The calculated potential energy barriers for the HNNH2 → NH + NH3 reaction (30-36 kcal mol-1) are larger than the potential energy barriers for the N2 → HNNH reaction (19-29 kcal mol-1). I propose that the post-HNNH slow step identified kinetically is the key HNNH2 → NH + NH3 reaction described here. This step and the N2-capture step are the most difficult in the conversion of N2 to 2NH3. The steps in the complete mechanism still to be computationally detailed are relatively straightforward.

Enhanced adsorption of bisphenol-A from water through the application of isocyanurate based hyper crosslinked resin

The widespread utility of Bisphenol A (BPA) in the production of diverse plastic substances including mineral water bottles, food packets, toys, tickets, etc. leads to its release to the environment through industrial effluents that contaminate both the surface and underground water. Given its higher toxicity and harmful effects on both human health and aquatic life, the adsorption of BPA has been the subject of recent studies at present. Herein, we disclose the synthesis of a new hyper cross-linked resin (ICYN-PPA), derived from commercially available 3,3′-(piperazine-1,4-diyl)bis(propan-1-amine) and tris(2,3-epoxypropyl) isocyanurate in a single step reaction, and its adsorptive performance for the removal of BPA from aqueous solution. The thermally stable ICYN-PPA, which is porous and exhibits different sizes of particles on its surface, displayed optimum removal of BPA. The isothermal studies were well represented by the Koble-Corrigan model, where the capacity increased from 216.6 to 228.6 mg g−1 with an increasing temperature of 318 K. The linear driving force model (LDF) was efficient in representing the kinetic data. Whereas the system tends to reach equilibrium after 350 min. The surface diffusion coefficients were 1.301 × 10−16 and 1.859 × 10−16 cm2 s−1 for BPA adsorption on isocyanurate based hyper crosslinked resins. The thermodynamic parameters confirmed the endothermic nature of the process (ΔH0 = 35.83 kJ mol−1) based on physical interactions.

Confined growth of Ag nanogap shells emitting stable Raman label signals for SERS liquid biopsy of pancreatic cancer

To develop a reliable surface-enhanced Raman scattering (SERS) immunoassay as a new liquid biopsy modality, SERS nanoprobes emitting strong and stable signals are necessary. However, Ag nanoparticles used as SERS nanoprobes are prone to rapid fading of SERS signals by oxidation. This has driven the development of a new strategy for Ag-based SERS nanoprobes emitting stable and strong SERS signals over time. Herein, Ag nanogap shells entrapping Raman labels are created in the confined pores of mesoporous silica nanoparticles (AgNSM) through a rapid single-step reaction for SERS liquid biopsy. Each AgNSM nanoprobe possesses multiple nanogaps of 1.58 nm to entrap Raman labels, allowing superior long-term SERS signal stability and large enhancement of 1.5 × 106. AgNSM nanoprobes conjugated with an antibody specific for carbohydrate antigen (CA)19-9 are employed in the SERS sandwich immunoassay including antibody-conjugated magnetic nanoparticles for CA19-9 detection, showing a two orders of magnitude lower limit of detection (0.025 U mL−1) than an enzyme-linked immunosorbent assay (0.3 U mL−1). The AgNSM nanoprobe immunoassay accurately quantifies CA19-9 levels from clinical serum samples of early and advanced pancreatic cancer. AgNSM nanoprobes with stable SERS signals provide a new route to SERS liquid biopsy for effective detection of blood biomarkers.

Visible-Light-Induced Photoredox 1,2-Dialkylation of Styrenes with α-Carbonyl Alkyl Bromides and Pyridin-1-ium Salts.

A visible-light-driven photoredox dialkylation of styrenes with α-carbonyl alkyl bromides and pyridin-1-ium salts for the synthesis of polysubstituted 1,4-dihydropyridines is reported. This reaction enables the formation of two new C(sp3)-C(sp3) bonds in a single reaction step and provides a strategy that employs pyridin-1-ium salts as the functionalized alkylating reagents via dearomatization to directly trap the resulting alkyl radicals from radical addition of alkenes and then terminate the alkene dialkylation.