P-toluenesulfonic Acid Research Articles

P-Toluenesulfonic Acid Modified Two-Dimensional ZrSe2 as a Hole Transport Layer for High-Performance Organic Solar Cells.

Two-dimensional (2D) materials have attracted attention due to their excellent optoelectronic properties, but their applications are limited by their defects and vacancies. Surface modification is an effective method to restore their performance. Here, ZrSe2 is modified with conductive polymer p-toluenesulfonic acid (PTSA). It is found that PTSA can obtain electrons of ZrSe2 through the combination of -SO3H and ZrSe2, thus forming interfacial dipoles, which improve the work function of ZrSe2. In addition, -OH in PTSA can effectively fill the Se vacancy in ZrSe2 to form P-type doping, thereby improving its conductivity. ZrSe2 modified by the PTSA material is first used as a hole transport layer (HTL) in organic solar cells (OSCs). The efficiency of OSCs based on the PBDB-T:ITIC and PM6:L8-BO binary active layer with ZrSe2:PTSA as the novel HTL reaches 10.66 and 18.14%, which are obviously higher than the efficiency of OSCs with pure ZrSe2 as the HTL (8.48 and 15.64%). More interestingly, the stability of the device with ZrSe2:PTSA as HTL is significantly better than that of PEDOT:PSS. This study shows that the modification of the organic material can effectively improve the photoelectric performance of ZrSe2 and explores the physical mechanism of the interaction between the organic modifier and 2D materials.

Preparation of a functional monomer containing polymerisable double bonds and chain transfer sulfhydryl groups

ABSTRACT Methacrylate functional monomers containing polymerisable double bonds and sulphhydryl group were synthesised using (methyl) hydroxyethyl (propyl) acrylate and mercaptopropionic acid as precursors with benzene (toluene, ethyl acetate, ether) as solvent and aqueous agent, p-toluene sulphonic acid as catalyst, hydroquinone as polymerisation inhibitor. The yield of methacrylate functional monomers was more than 90%. The structure and purity of methacrylate functional monomers was characterised by proton nuclear magnetic resonance (1H-NMR) and liquid chromatography–mass spectrometry (LC-MS). The precursor material source is of low cost and widely available, and the product did not need to be purified by a special method, which means that it can be directly used for the synthesis of vinyl branched polymer. Therefore, the price of vinyl branched polymer can be greatly reduced and the application range of vinyl branched polymer can be greatly expanded.

Complete kinetic model for esterification reaction of lauric acid with glycerol to synthesize glycerol monolaurate

Glycerol monolaurate (GML) is a widely used industrial chemical with excellent emulsification and antibacterial effect. The direct esterification of glycerol with lauric acid is the main method to synthesize GML. In this work, the kinetic process of direct esterification was systematically studied using p-toluenesulfonic acid as catalyst. A complete kinetic model of consecutive esterification reaction has been established, and the kinetic equation of acid catalysis was deduced. The isomerization reactions of GML and glycerol dilaurate were investigated. It was found that the reaction was an equilibrium reaction and the reaction rate was faster than the esterification reaction. The kinetic equations of the consecutive esterification reaction were obtained by experiments as k1=(276+92261Xcat)exp(−37720/RT) and k2=(80+4413Xcat)exp(−32240/RT). The kinetic results are beneficial to the optimization of operating conditions and reactor design in GML production process.

PTSA-induced synthesis, in silico and nano study of novel ethylquinolin-thiazolo-triazole in cervical cancer.

Aim: p-Toluenesulfonic acid-(PTSA) and grinding-induced novel synthesis of ethylquinolin-thiazolo-triazole derivatives was performed using green chemistry. Materials & methods: Development of a nanoconjugate drug-delivery system of ethylquinolin-thiazolo-triazole was carried out with D-α-tocopheryl polyethylene glycol succinate (TPGS) and the formulation was further characterized by transmission electron microscopy, atomic force microscopy, dynamic light scattering and in vitro drug release assay. The effect of 3a nanoparticles was assessed against a cervical cancer cell line (HeLa) through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the effect on apoptosis was determined. Results & discussion: The 3a nanoparticles triggered the apoptotic mode of cell death after increasing the intracellular reactive oxygen level by enhancing cellular uptake of micelles. Furthermore, in silico studies revealed higher absorption, distribution, metabolism, elimination and toxicity properties and bioavailability of the enzyme tyrosine protein kinase. Conclusion: The 3a nanoparticles enhanced the therapeutic potential and have higher potential for targeted drug delivery against cervical cancer.

Conversion of 5-hydroxymethylfurfural and carbohydrates to 5-ethoxymethylfurfural over chitin-derived solid acid catalysts

The use of environment friendly biomass-based catalysts in bio refinery is highly desirable. In this paper, the preparation of sulfonated carbon materials from biopolymers (typically chitin and cellulose) via facile one-step carbonization and sulfonation using p-toluenesulfonic acid as sulfonating agent was demonstrated. Unlike nitrogen-free cellulose, the basic nitrogen-containing sites generated from chitin decreased the acidity strength of the catalysts, which was confirmed by the results of 31P Nuclear Magnetic Resonance (31P NMR). The suppressed acidity strength boosted the selectivity of 5-ethoxymethylfurfural (EMF) from 5-hydroxymethylfurfural (HMF) by inhibiting the formation of by-products, such as ethyl levulinate (EL) and humins. An 84.3 % yield of EMF from HMF was obtained over the as-prepared chitin-derived solid acid. The catalyst could be reused at least three times without obvious decrease of catalytic activity. Moreover, 74.6 %, 31.9 % and 60.7 % yields of EMF were obtained from fructose, sucrose and inulin in ethanol-containing solvents, respectively. This work offers an example for the synthesis of biofuels using biomass-derived catalysts.

Preparing vegetable oils-based metalworking fluids by a hydrolysis-esterification two-step process

Oil-soluble esters of free fatty acids were synthesized with a 2-step process including the first step of reacting vegetable oil with water in the presence of sulfuric acid and p-Toluenesulfonic acid as a catalyst, followed by removing water and glycerol, and the second step of reacting the obtained free fatty acids with various polyhydric and fatty alcohols. The best conditions were 190 °C, 6 h, 30 to 1 water to oil molar ratio, 5 wt% PTSA catalyst loading in the hydrolysis reaction (the 1st step), and 150 °C, 10 h, 4 to 1 fatty acid to trimethylolpropane molar ratio, 1 wt% PTSA catalyst loading in the esterification reaction (the 2nd step). Under the best conditions, the process achieved the final product with the 87% yield of free fatty acid trimethylolpropane ester and 82% conversion of free fatty acid. Different esters were made concurring to the aforementioned conditions with distinctive polyhydric and fatty alcohols. Hydrolysis reactions facilitated by catalysts offer an alternative approach to traditional hydrolysis in supercritical conditions, enabling efficient substrate conversion under milder operating conditions. Furthermore, the inclusion of the obtained esters mixed with base oil and additives produced bio-based metalworking fluids with exceptionally lubricant performance in wear resistance, with a wear scar diameter of 0.33 mm.

Integrated preparation of functional lignin nanoparticles and levulinic acid directly from the pre-hydrolysis liquor of poplar wood

The pre-hydrolysis liquor (PHL) produced during pulp dissolution and biomass refining is mainly composed of hemicellulose and lignin, and it is a potential source for production of value-added materials and platform chemicals; however, their utilization has been a serious challenge. In this study, we proposed a green and simple strategy to simultaneously prepare size-controlled functional lignin nanoparticles (LNPs) and levulinic acid (LA) from PHL as the raw material. The as-prepared LNPs exhibited remarkable stability thanks to the presence of saccharides with abundant oxygen-containing groups and surface charges, which prevented aggregation and maintained long-term storage stability. Trace amounts of the LNPs (≤ 0.2 wt%) could stabilize various Pickering emulsions, even with oil-to-water ratios as high as 5:5 (v/v). Subsequently, the remaining PHL was directly used to produce LA without adding a catalyst; under optimal conditions (160 °C and 1 h), the yield of LA was 56.3 % based on the dry saccharide content in the raw PHL. More importantly, p-toluenesulfonic acid (p-TsOH), the only reactive reagent used during the entire preparation process, including the two preparation steps of the LNPs and LA, was reusable, and the recovery rate was >70 % after five cycles. Overall, this green and simple strategy effectively and comprehensively utilized the PHL and showed potential for producing biobased nanomaterials and platform chemicals.

In-situ approach to porous nitrogen-doped carbon nanosheets functionalized by Brønsted acidic ionic liquids for microwave-assisted upgrading fructose to 5-hydroxymethylfurfural

In the search for robust and recoverable supported Brønsted acidic ionic liquids (BAILs) catalysts for efficient upgrading bio-sugars to value-added chemicals, an in-situ strategy of supramolecular preorganization-thermal polycondensation is designed to fabricate porous ultrathin nitrogen-doped carbon nanosheets (NCNSs), and then BAILs-functionalized NCNSs catalysts are prepared via successive quaternary ammonization by sultones and anion exchange with Brønsted acids. By adjusting the molar composition of the starting monomers, the textural properties of NCNSs supports are tuned; and by functionalization with different sultones (1,3-propanesultone and 1,4-butanesultone) and organic (trifluoromethanesulfonic acid and p-toluenesulfonic acid) or inorganic (H2SO4 and H3PO4) acids, the surface hydrophobicity and Brønsted acid strength of the catalysts are regulated. The catalysts are applied in microwave-assisted upgrading fructose to 5-hydroxymethylfurfural, and influences of Brønsted acid nature, surface hydrophobicity and textural properties on the catalytic performance are explored. For the most active [C4SO3HN][OTf]-NCNSs-MA-3 catalyst with the advantages of superstrong Brønsted acidity, higher surface hydrophobicity and perfect porous ultrathin sheet-like nanostructure, the conversion of fructose and the yield of 5-hydroxymethylfurfural of 100% and 87.7% are achieved after microwave irradiation for 15 min, outperforming Amberlyst-15 resin and HY zeolite. The catalysts also demonstrate the robust catalytic reusability, and after five consecutive catalytic runs, the obvious activity loss hardly occurs, along with little acid sites leaching.

Brønsted Acid-Catalyzed Diastereoselective Synthesis of Spiroisoindolinones from Enamides.

A highly diastereoselective synthesis of spiroisoindolinones from enamides and 3-hydroxy-isoindolinones is reported. The reaction proceeds rapidly in the presence of p-toluenesulfonic acid as a Brønsted acid catalyst and affords a variety of densely substituted spiroisoindolinones with three contiguous stereogenic centers in high yields (≤98%) and diastereoselectivities (up to dr >98:<2:0:0).

Facile synthesis of functional binaphthyl-based hyperbranched polyarylenes by organo-catalyzed alkyne polycyclotrimerization

Binaphthyl-based polymers have attracted increasing interest due to their unique properties and wide applications. Nevertheless, binaphthyl-containing hyperbranched polymers are rarely reported. Herein, two binaphthyl-based hyperbranched polyarylenes with high molecular weights were facilely synthesized in satisfactory yields by the polycyclotrimerization of internal diynes containing binaphthyl units in 1,2,4-trichlorobenzene (TCB) under heating in the presence of p-toluenesulfonic acid monohydrate (p-TsOH·H2O). The resultant polymers are soluble in common organic solvents, and thermally stable with 5% weight loss temperatures higher than 380 °C. They showed electrochemical properties, and optical activities. Furthermore, the polymer-doped polyvinyl alcohol (PVA) films exhibited yellow room-temperature phosphorescence (RTP) with the lifetime longer than 630 ms.

Combination of microwave with acid deep eutectic solvent pretreatment for reed (Phragmites australis) fractionation

The cost-effective and low-carbon fractionation of lignocellulosic biomass will enhance the economic viability of bio-refining. To achieve efficient reed fractionation under favorable conditions, microwave-assisted choline chloride and p-toluene sulfonic acid (M-ChCl/p-TsOH) pretreatment was employed. The fractionation of reed components demonstrated higher effectiveness with M-ChCl/p-TsOH pretreatment compared to conventional DES pretreatment. Under M-ChCl/p-TsOH conditions, a high hemicellulose removal rate (∼90%) and delignification rate (∼65%) were achieved while achieving a saccharification rate of 88% during cellulase hydrolysis. Microwave assistance not only significantly reduced reaction time to less than 60 s but also enhanced the pretreatment efficacy. Furthermore, the obtained lignin products consisted of low-polymerization lignin (MW < 800 g/mol) and acid-soluble lignin, providing a solid foundation for subsequent high-value utilization of lignin. This study provides a promising strategy for the low carbon fractionation of reed using DES, aiming to simultaneously achieve efficient cellulose hydrolysis and obtain tractable lignin.

Investigation into the characteristics of bagasse processed with 3C-DES and the production of chemimechanical pulp for pulp molded

Pulp molded generated from renewable bagasse as biodegradable packaging materials has been widely viewed as an eco-friendly and cheap way to substitute the current huge consumption of nondegradable plastics, and deep eutectic solvents (DES) pretreatment are a promising approach to obtain high-yield pulp efficiently and sustainably. However, mainstream binary-component DES still suffers issues of high viscosity and corrosiveness. This study put forward a ternary-component DES (3C-DES) with the addition of ethylene glycol (EG) into choline chloride (ChCl) and P-toluenesulfonic acid (PTSA) and examined pretreatment performance and optimal DES ratio for thread rolling bagasse via compositional analysis and physicochemical characterization. Moreover, density functional theory calculations were used to reveal structures and weak interactions of different ratios of 3C-DES, and a novel 3C-DES pretreatment chemical-mechanical pulp and pulp molded were finally prepared. The results indicate that the 3C-DES with ChCl:PTSA:EG molar ratio of 1:1:3 is most effective, evidenced by more than 97.94% lignin removals. The 3C-DES pretreated mechanical pulp exhibits superior fiber properties, whereas the hot-pressed pulp molded shows excellent physical properties and thermal stability. Thus, the proposed 3C-DES has great potential to obtain high-yield high-performance pulp molded with low cost and environmental sustainability.

A Molecular Modeling Study into Brønsted and Lewis Acid Catalyzed Conversion of CBD into Other Cannabinoids

A Molecular Modeling Study into Brønsted and Lewis Acid Catalyzed Conversion of CBD into Other Cannabinoids

Versatile stereoselective oxidative alkoxycarbonylation of styrenes at room-temperature

Carbonylation reactions carried out at room temperature and at atmospheric pressure of carbon monoxide are highly attractive and extremely rare at the same time. Here, the oxidative alkoxycarbonylation of styrenes to industrially relevant cinnamates has been developed under such a mild conditions (rt, 1 atm of CO) in the presence of a palladium(II) complex bearing a bis(aryl)acenaphthenequinonediimine ligand, benzoquinone and p-toluenesulfonic acid. Remarkably, variously substituted styrene derivatives have been efficiently carbonylated using a nearly stoichiometric amount of alcohols, with a dramatic reduction of waste. Even reluctant internal alkenes have shown to be compatible under these carbonylative conditions. In consideration of experimental results and DFT calculations a mechanistic rationale has been proposed. Based on this study, the benzoquinone has been found to promote the final palladium reoxidation, and to boost the reaction under such unprecedent mild conditions. The present methodology has been successfully exploited for the synthesis of high value-added cinnamoyl glycerols and cinnamic acid sugar esters, including the 6-O-p-coumaroyl-D-glucose natural product.

An Efficient Access to Heteroaryl/Aryl-Annulated Pyridine Derivatives and a Study of Their Mosquito Larvicidal Activity Against Dengue Vector

AbstractWe report a convergent synthesis of heteroaryl/aryl-annulated pyridine and quinoline derivatives by a metal-free Povarov reaction. para-Toluene sulfonic acid was used as the catalyst in this reaction, which produced the products in good yields from the corresponding aromatic amines and ethyl vinyl ether. A pyridocoumarin and a pyridopyrimidine product were evaluated for their mosquito larvicidal activity against the third instar larvae of the dengue vector mosquito Aedes aegypti. Examination of morphological changes in the larvae showed damage to the target body part after treatment with both the pyridocoumarin and pyridopyrimidine products at the LC50 concentrations.

Meglumine-based Sustainable Three-component Deep Eutectic Solvent Applicable for the Synthesis of Pyrazolo[5,1-b]quinazoline-3-carboxylates as a Sensing Probe for Cu2+ Ions.

An unprecedented meglumine-based three-component deep eutectic solvent (3c-DES) (MegPAc) was synthesized using meglumine, p-toluenesulfonic acid (PTSA), and acetic acid as a renewable, and non-toxic solvent. The exploitation of the MegPAc as an eco-friendly reaction media to construct a selective and sensitive small organic molecular sensing probe, namely, pyrazolo[5,1-b]quinazoline-3-carboxylates (PQCs) was executed. Captivatingly, the MegPAc served the dual role of solvent and catalyst, and it delivered the title components with 69-94 % yields within 67-150 minutes. Furthermore, a UV-visible study unfolds the selective detection of Cu2+ ions with our synthetic probe 4 ba and resulted in hypsochromic shift due to electrostatic interactions. Additionally, 1H NMR titration study and density functional theory (DFT) calculations were performed to attest the binding mechanism of sensing probe 4 ba and Cu2+ ions. Worthy of mention, this protocol unveils the efficacy of meglumine-based 3c-DES for the first time as a bio-renewable system to synthesize the PQCs.

Study of Electrical and Mechanical Properties of Polypyrrole-Coated Three-Dimensional Spacer Fabric

In this study, the liquid phase oxidative polymerization method was utilized to prepare polypyrrole conductive three-dimensional spacer fabrics. By controlling pyrrole solution, oxidant FeCl3 solution, dopant p-toluene sulfonic acid concentration and reaction time, the optimal process for the preparation of conductive spacer fabrics was obtained. This led to the best preparation process of polypyrrole-coated three-dimensional spacer conductive fabric (polypyrrole/three-dimensional spacer fabrics) being obtained. The results showed that the conductive properties of polypyrrole/three-dimensional spacer fabrics were the best when 0.10 mol/L pyrrole, 0.40 mol/L oxidant FeCl3 solution, and 0.40 mol/L dopant p-toluene sulfonic acid were prepared within a 2-h reaction time. The properties of polypyrrole/three-dimensional spacer fabrics were analyzed using the results from surface resistance, Fourier transform-infrared spectroscopy, mechanical properties, and stability tests. The results showed that polypyrrole was well attached to the three-dimensional spacer fabric surface, and the concentration of polypyrrole in the fabric exhibited an inverse correlation with changes in surface resistance. The mechanical properties of polypyrrole/three-dimensional spacer fabrics after treatment exhibit superior performance, with consistent changes in the meridional and zonal electrical properties during tensile testing and can maintain excellent long-term electrical stability in atmospheric environments.

Oxidation of p-toluenesulfonic acid fractionated hybrid Pennisetum by different methods for carboxylated nanocellulose preparation: The evaluation of efficiency and sustainability

An innovative two-step process with p-toluenesulfonic acid (p-TsOH) and oxidation treatment was proposed for the efficient preparation of carboxylated nanocellulose from hybrid Pennisetum. Approximately 90 % of lignin was dissolved by p-TsOH acid under the optimal condition (80 °C, 20 min). Near-complete delignification (down to 0.5 %) and introduction of carboxylate groups (up to 1.48 mmol/g) could be achieved simultaneously during cellulose oxidation treatments without the requirement for bleaching. However, different oxidation methods expressed different efficiency and sustainability. 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) oxidation has higher selectivity for the carboxylation reaction but with detriment to the aquatic environment. Fenton oxidation is more energy-consuming due to the lower carboxylate contents of products (maximum 188 μmol/g), with the carboxylic groups present as carboxylic acids, but competitive in terms of environmental sustainability, especially when renewable energy sources are available. The nanocelluloses obtained by the two oxidation methods differ in morphology and have different application prospects.

Synthesis of isobutyl cinnamate based on DESs catalyst: Optimization and kinetics

AbstractIn this work, the optimum process conditions and kinetics of the green synthesis of isobutyl cinnamate using deep eutectic solvents (DESs) as catalysts were investigated. Isobutyl cinnamate is a spice with low toxicity and is widely used in the food industry. However, there is a lack of reports on its green synthesis. Three DESs were prepared by adjusting the mixing ratio of choline chloride (ChCl) and p‐toluenesulfonic acid (PTSA). Response surface methodology with Box‐Behnken design (RSM‐BBD) was used to optimize the process parameters of the esterification of cinnamic acid with isobutanol. The effects of catalyst loading, stirring speed, cinnamic acid/isobutanol molar ratio, and temperature on the conversion of cinnamic acid over time were evaluated. Using ChCl‐PTSA as a catalyst, the kinetics data and chemical equilibrium constants of the esterification were determined at a temperature range of 353.15–383.15 K. The pseudo‐homogeneous (PH) model based on activity was then adopted to describe the kinetics of the reaction, and the relative deviations between the experimental values and the calculated ones by PH model are less than 5.5%. Thermodynamic data (ΔrH0, ΔrS0, ΔrG0) for the esterification reaction was calculated as well. In addition, the results of six consecutive cycles of the catalyst showed that ChCl‐PTSA has good stability and recyclability.

Unraveling the mechanisms underlying lignin and xylan dissolution in recyclable biphasic catalytic systems

Despite the exceptional performance of recyclable biphasic pretreatment systems (i.e., p-toluenesulfonic acid (TsOH)/pentanol, H2SO4/butanol, and AlCl3/MTHF) in the holistic fractionation of lignocellulosic biomass (LCB), there remains a significant gap in understanding of the intricate mechanisms governing the rapid dissolution of lignin and xylan from LCB. This study conducts comparative analyses using laboratory experiments and computational simulations to gain insights into the mechanism behind removing lignin and xylan in these systems. Under identical pretreatment conditions (140 °C, 45 min), three systems exhibited distinct levels of delignification and xylan removal. TsOH/pentanol showcased the highest levels of both delignification (83.3%) and xylan removal (98.1%), followed by H2SO4/butanol (77.9% delignification and 83.0% xylan removal), and AlCl3/MTHF (73.5% delignification and 97.2% xylan removal). Lignin characterization revealed that TsOH/pentanol and AlCl3/MTHF lignin samples boasted well-preserved β-O-4 bonds (42.4/100 Ar, 40.4/100 Ar, respectively), uniform molecular weights, and <1% sugar content. This led to high yields of phenolic monomers (TsOH/pentanol, 33.9%; AlCl3/MTHF, 33.7%) after catalytic hydrogenolysis of lignin. Furthermore, mechanistic analyses revealed that the TsOH/pentanol and AlCl3/MTHF systems exhibited the most significant interaction energy formation with the lignin model (veratrylglycerol-b-guaiacyl ether) and D-xylan model due to robust hydrogen bonding interactions, yielding energy values of −2460 kJ/mol and −2385 kJ/mol, respectively. These interactions could play pivotal roles in accomplishing notable lignin and xylan extraction.