Triethyl Benzyl Ammonium Research Articles

Facile fractionation of poplar by a novel ternary deep eutectic solvent (DES) for cellulosic ethanol production under mild pretreatment conditions

The efficient fractionation of lignocellulosic biomass using deep eutectic solvent (DES) is emerging as an innovative and eco-friendly approach. In this study, a novel ternary DES composed of triethylbenzyl ammonium chloride (TEBAC), p-toluene sulfonic acid (TsOH), and ethylene glycol (EG) was employed for the pretreatment of poplar wood to enhance cellulosic ethanol production. Key pretreatment parameters, including temperature, DES molar ratios, and reaction time, were systematically optimized. Under optimal conditions (90 ºC, 60 min, TEBAC/TsOH/EG ratio of 1:1.5:3) lignin removal reached 90.64±1.28 % and xylan removal achieved 85.56±1.34 %, significantly improving cellulose digestibility. The improvement might be attributed to the removal of hemicellulose and lignin, which exposed cellulose and enhanced the accessibility of cellulase to cellulose. Additionally, optimized enzymatic hydrolysis yielded a glucose concentration of 65.98±0.97 g/L using an enzyme loading of 15 FPU/g poplar and a solid loading of 13.33 %. Furthermore, during pre-hydrolysis combined with simultaneous saccharification and fermentation (PSSF), an ethanol concentration of 37.58±0.23 g/L was achieved. Overall, this study demonstrates a novel ternary DES pretreatment method that effectively facilitates the fractionation and conversion of woody biomass into cellulosic ethanol.

Copper bromide complexes with triethylbenzylammonium (TEBA): the ladder complex (TEBA)2Cu2Br6, the polymorph dimer α-(TEBA)2Cu2Br6, and the monomeric salt (TEBA)2CuBr4

Two new complexes of copper(II) with bromide ligands and triethylbenzylammonium (TEBA) cations are reported, α-(TEBA)2[Cu2Br6] (1), and (TEBA)2[CuBr4] (2). The syntheses, crystal structures, and magnetic properties are described. 1 crystallizes as bibromide bridged dimers which are linked into square layers via short Br…Br contacts. Variable temperature magnetic susceptibility data indicate ferromagnetic interactions within the dimers (J/kB = 107(4) K) with weak interdimer antiferromagnetic interactions (θ = −3.47(6) K). 2 crystallizes as discrete tetrabromidocuprate anions which are well isolated by the bulk of the TEBA cations. Magnetic susceptibility measurements indicate negligible magnetic interactions in the material. The magnetic properties of the known polymorph (TEBA)2[Cu2Br6] (3) were reexamined in light of the properties of 1 and suggest a significantly stronger interaction within the dimer (J/kB ∼ 110(4) K) than originally proposed. These findings are in agreement considering the nearly identical structures of the Cu2Br6 2- dimers in 1 and 3.

High-performance removal of methylene blue dye using porous lignin extracted from sugarcane bagasse by deep eutectic solvent

This study evaluated the ability of triethyl benzyl ammonium chloride/lactic acid deep eutectic solvent extracted lignin (TEBAC/LA-DES-L) to adsorb methylene blue (MB) without additional functional group modification. The structure and morphology of TEBAC/LA-DES-L were characterized using SEM, BET, FT-IR, and TGA techniques. Various factors influencing MB adsorption, such as extraction temperature, solution pH, adsorbent dose, initial MB concentration, adsorption time, and reaction temperature, were investigated. The Redlich-Peterson isotherm displayed a good fit for the experimental data, with a maximum adsorption capacity of 85.16 mg/g. Kinetic analysis suggested that the adsorption process followed the pseudo-second-order model, with adsorption occurring in <100 min on DES-L-4 h. The mechanism of MB adsorption on DES-L-4 h was attributed to electrostatic attraction, hydrophobic interactions, and hydrogen bonding forces. Overall, DES-L-4 h demonstrated high adsorption capacity and rapid adsorption rate, making it a promising adsorbent for effectively removing cationic dyes from wastewater.

Cascade fractionation of bamboo shoot shells into high-yield xylose, easily digestible cellulose and high-quality lignin nanoparticles by tailored catalytic hydrothermal–hydrated alkaline deep eutectic solvents pretreatment

The high complexity and compactness of inherent structure in lignocellulosic materials (LCM) leads to the difficulty of fractionation and conversion of its major component, which is the key obstacle limiting the value-added utilization of LCM. In this work, a cascade fractionation strategy, coupling catalytic hydrothermal pretreatment (CHTP, choline chloride: ethylene glycol: AlCl3, ChCl/ EG/ AlCl3) with hydrated alkaline deep eutectic solvent (HADES, triethylbenzyl ammonium chloride/ethanolamine, TEBAC/EM) treatment, was proposed to fractionate dendrocalamus latiftorus munro shoot shells (DLMSS). The results showed that considerably high hemicelluloses removal (94.57 %) and xylose yield (90.73 %) were achieved by the first step (CHTP, 160 °C, 1 h, 2 % of catalyst loading). The cascaded HADES treatment realized 90.25 % delignification ratio under the optimal conditions (120 °C, 3 h, 75 % of ADES loading), and the obtained residue could be easily converted into high-yield (93.35 %) of glucose via enzymatic saccharification. In addition, multiple enrichment cycle strategy (MECS) was performed to facilitate the recyclability of the HADES. The results showed that the enriched lignin recovered by MECS was activated by in-situ demethoxylation reaction. And such lignin fraction could be easily assembled into homogeneous lignin nanoparticles (LNPs, ∼31.51 nm in diameter) by simple sonication. Meanwhile, the MECS signally energized the antioxidant activity of the enriched lignin. Based on the high-efficiency cascade fractionation with the coupled CHTP-HADES fractionation strategy, it will observably boost the effectiveness and scalability of the advanced biorefinery strategy.

Aromatic volatile organic compounds absorption with phenyl‐based deep eutectic solvents: A molecular thermodynamics and dynamics study

AbstractThe suitability of phenyl‐based deep eutectic solvents (DESs) as absorbents for toluene absorption was investigated by means of thermodynamic modeling and molecular dynamics (MD). The thermodynamic models perturbed‐chain statistical associating fluid theory (PC‐SAFT) and conductor‐like screening model for real solvents (COSMO‐RS) were used to predict the vapor–liquid equilibrium of DES–toluene systems. PC‐SAFT yielded quantitative results even without using any binary fitting parameters. Among the five DESs studied in this work, [TEBAC][PhOH] consisting of triethyl benzyl ammonium chloride (TEBAC) and phenol (PhOH), was considered as the most suitable absorbent. Systems with [TEBAC][PhOH] had lowest equilibrium pressures of the considered DES–toluene mixtures, the best thermodynamic characteristics (i.e., Henry's law constant, excess enthalpy, Gibbs free energy of solvation of toluene), and the highest self‐diffusion coefficient of toluene. The molecular‐level mechanism was explored by MD simulations, indicating that [TEBAC][PhOH] has the strongest interaction of DES–toluene compared to the other DESs under study. This work provides guidance to rationally design novel DESs for efficient aromatic volatile organic compounds absorption.

Process optimization for deep eutectic solvent pretreatment and enzymatic hydrolysis of sugar cane bagasse for cellulosic ethanol fermentation

This study investigated cellulosic ethanol production from sugar cane bagasse (SCB) pretreated by triethylbenzyl ammonium chloride/lactic acid (TEBAC/LA) deep eutectic solvent (DES). The results showed that the pretreatment of SCB with TEBAC/LA DES at 120 °C for 4 h with 1:15 (solid to liquid ratio) resulted in the best cellulose digestibility (88.23 ± 1.24%), which was approximately 228% higher than that of untreated SCB. Furthermore, the maximum cellulosic ethanol concentration of 16.84 g/L was achieved using glucose (36.06 g/L) and xylose (7.36 g/L). Moreover, the ethanol productivity and yield were 0.70 g/(L·h) and 0.42 g/g fermentable sugar, respectively. The efficient bioconversion was ascribed to the remarkable delignification (88.72 ± 1.63%), xylan removal (73.93 ± 0.17%), along with optimum cellulose recovery (95.89 ± 1.54%). Importantly, the enzymatic hydrolysis digestibility remained unchanged after 5 times DES recycling process. Overall, it also provided an insight into the efficient SCB biorefinery of DES systems.

Synthesis and reactions of alkenyl-gem-dichlorocyclopropanes obtained from piperylene

Objectives. This study aims to obtain alkenyl-gem-dichlorocyclopropanes from piperylene. The products are then subjected to thermocatalytic isomerization and hydrogenation.Methods. To determine the qualitative and quantitative composition of the reaction crudes, the following analytical methods were used: gas-liquid chromatography using the Crystal 2000 hardware complex, mass spectrometry using a Chromatec-Crystal 5000M device with the NIST 2012 database, and nuclear magnetic resonance (NMR) spectroscopy using a Bruker AM-500 device at operating frequencies of 500 and 125 MHz.Results. Alkenyl-gem-dichlorocyclopropanes were synthesized in the presence of triethylbenzyl ammonium chloride as catalyst. Their isomerization and hydrogenation gave the corresponding gem-dichlorocyclopentene and isomers of alkyl-gem-dichlorocyclopropanes. The structure of synthesized substances were analyzed by gas-liquid chromatography, mass spectrometry, and NMR spectroscopy.Conclusions. The results show that formation of four isomeric substituted gemdichlorocyclopropanes occurs in high yield during incomplete dichlorocyclopropanation of piperylene. The thermocatalytic isomerization of substituted gem-dichlorocyclopropanes in the presence of SAPO-34 zeolite leads to the formation of one product, i.e., gem-dichlorocyclopentene, and hydrogenation of substituted gem-dichlorocyclopropanes in the presence of Pd/C catalyst gives three isomeric alkyl-gem-dichlorocyclopropanes.

Enhanced Enzymatic Hydrolysis and Lignin Extraction of Wheat Straw by Triethylbenzyl Ammonium Chloride/Lactic Acid-Based Deep Eutectic Solvent Pretreatment.

Efficient and feasible pretreatment of lignocellulosic biomass waste is an important prerequisite step to promote subsequent enzymatic hydrolysis and enhance the economics of biofuels production. This study focuses on the pretreatment of wheat straw (WS) with triethylbenzyl ammonium chloride/lactic acid (TEBAC/LA)-based deep eutectic solvents to enhance biomass fractionation and lignin extraction. Effects of pretreatment time, temperature, and TEBAC/LA molar ratio on pretreatment were evaluated systematically. Results suggested that 89.06 ± 1.05% of cellulose and 71.00 ± 1.03% of xylan were hydrolyzed with enzyme loadings of 35 FPU cellulase and 82 CBU β-glucosidase (per gram of dry biomass) after pretreatment by TEBAC/LA (1:9) at 373 K for 10 h. A total monosaccharide yield of 0.550 g/g WS (91.27% of the theoretical yield) was achieved with 79.73 ± 0.93% of lignin removal. Furthermore, the 1H–13C two-dimensional heteronuclear single quantum correlation (2D-HSQC) NMR spectroscopy showed that the regenerated lignin (75.69 ± 1.32% purity) was mainly composed of the syringyl units and the guaiacyl units. Overall, the results in this study provide an effective and facile pretreatment method for lignocellulosic biomass waste to enhance enzymatic hydrolysis saccharification.

Synthesis of a new bis(perfluoroalkyl oxirane) dioxyethylene ether

Classic direct synthetic methods failed to transform bis(perfluororalkylallyl) dioxyethylene ether into the corresponding bis(perfluoroalkyl oxirane). This transformation was instead realized using a mixture of mercuric acetate/bromine to produce the corresponding bromoacetate, which was subsequently transformed to a bromohydrin and further to bis(perfluoroalkyl oxirane) through the use of triethylbenzyl ammonium chloride as a phase transfer catalyst in alkaline media.

Triethyl benzyl ammonium chloride (TEBAC) catalyzed solvent-free one-pot synthesis of pyrimido[4,5-d]pyrimidines

A series of pyrimido[4,5-d]pyrimidine derivatives were synthesized by a multicomponent reaction of urea/thiourea, aldehyde and barbituric or thiobarbituric acid in the presence of triethyl benzyl ammonium chloride as a catalyst under solvent-free conditions. The pure products were obtained after recrystallization from ethanol. All synthesized compounds were characterized using IR and NMR (1H and 13C) spectroscopic and elemental analyses data.

Effective Synthesis of tert-Butyl-Substituted 3-Carboxy Coumarins in Water Using TEBAC as Catalyst

A facile synthesis of novel tert-butyl substituted 3-carboxycoumarin derivatives is described, featuring the one-pot reaction of tert-butyl substituted salicylaldehydes with Meldrum's acid in water using triethylbenzyl ammonium chloride (TEBAC) as catalyst.

Synthesis and in vitro Antibacterial Activities of 5‐(2,3,4,5‐Tetrahydro‐1H‐chromeno[2,3‐d]pyrimidin‐5‐yl)pyrimidione Derivatives

AbstractA series of novel 5‐(2,3,4,5‐tetrahydro‐1H‐chromeno[2,3‐d]pyrimidin‐5‐yl)pyrimidione derivatives have been synthesized from substituted salicylaldehydes and barbituric acid or 2‐thiobarbituric acid in water catalyzed by phase transfer catalysis of triethylbenzyl ammonium chloride (TEBA). Elemental analysis, IR, 1H NMR, and 13C NMR elucidated the structures of all the newly synthesized compounds. In vitro antimicrobial activities of synthesized compounds have been investigated against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. These newly synthesized derivatives exhibited significant in vitro antibacterial activity.

Electrospinning and cutting of ultrafine bioerodible poly(lactide‐co‐ethylene oxide) tri‐ and multiblock copolymer fibers for inhalation applications

AbstractTriblock copolymers made up of poly(ethylene oxide) (PEO) and polylactide (PLA) were synthesized and converted to fibers by the electrospinning process. A two‐step in situ‐synthesis in bulk was applied to extend PLA‐PEO‐PLA triblock copolymers with relatively short block length and low molecular weight in order to obtain electrospinnable materials. DL‐lactide was polymerized to the hydroxyl chain ends of PEO via the stannous octoate route. Hexamethylene diisocyanate (HDI) was added as chain extender in the second step, leading to poly(ether‐ester‐urethane) multiblock copolymers. The materials were electrospun from solutions in chloroform. Different concentrations and voltages were analyzed. The ether and ester blocks were varied in their block length and their effects on the fiber morphology was studied. Variations in the electrical conductivity of the chloroform solutions were investigated by adding triethyl benzyl ammonium chloride (TEBAC) in different amounts. Finally, with high quality electrospun PLA‐PEO‐PEO triblock copolymer fibers mechanical cutting was possible. Copyright © 2009 John Wiley &amp; Sons, Ltd.

Novel Zinc Ion–Catalyzed Synthesis of Unsymmetric Multisubstituted Pyridines

A facile and convenient synthesis of unsymmetric multisubstituted pyridines from β-ketoesters and ketene N,S-acetals or ketene N,N-acetals has been achieved in good yields catalyzed by Zn(NO3)2·6H2O in the presence of triethylbenzylammonium (TEBA) chloride in ethanol. This reaction was carried out under economical, one-pot reaction conditions (using easily obtained starting materials, and inexpensive catalyst and solvent) and offers considerable improvements over traditional methodology.

Syntheses of cyclic polycarbonates by the direct phosgenation of bisphenol M

AbstractBisphenol M was subjected to interfacial polycondensations in an NaOH/CH2Cl2 system with triethylamine as a catalyst. Regardless of the catalyst concentration, similar molecular weights were obtained, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectra exclusively displayed mass peaks of cycles (detectable up to 15,000 Da). With triethyl benzyl ammonium chloride as a catalyst, linear chains became the main products, but the contents of the cycles and the molecular weights strongly increased with higher catalyst/bisphenol ratios. When the pseudo‐high‐dilution method was applied, both diphosgene and triphosgene yielded cyclic polycarbonates of low or moderate molecular weights. Size exclusion chromatography measurements, evaluated with the triple‐detection method, yielded bimodal mass distribution curves with polydispersities of 5–12. Furthermore, a Mark–Houwink equation was elaborated, and it indicated that the hydrodynamic volume of poly(bisphenol M carbonate) was quite similar to that of poly(bisphenol A carbonate)s with similar concentrations of cyclic species. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1248–1254, 2005

Hydrolytic Polycondensation of Bisphenol‐A‐Bischloroformate Catalyzed by Phase‐Transfer Catalysts

AbstractThe hydrolytic interfacial polycondensation of bisphenol‐A‐bischloroformate was performed with four different phase‐transfer (PT) catalysts: N‐butylpyridinium bromide, triethylbenzylammonium (TEBA) chloride, tetrabutylammonium hydrogen sulfate, and tetraphenylphosphonium bromide. These polycondensations were conducted at 5 or 35 °C initial reaction temperature. The resulting polycarbonates were characterized by viscosity and SEC measurements and by MALDI‐TOF mass spectrometry. The four PT catalysts gave quite different results with respect to molecular weight and formation of cyclic polycarbonates. The highest molecular weights (number average, $\overline M _{\rm n} \approx 215\;{\rm kDa}$ and weight average, $\overline M _{\rm w} \approx 600\;{\rm kDa}$) were obtained with TEBA‐Cl. Lower temperatures and high feed ratios of TEBA‐Cl proved to be favorable for both high molecular weights and high fractions of cycles. Cyclic polycarbonates were detectable in the mass spectra up to 14 kDa (technical limit of the measurements). Low molecular weights in combination with unreacted chloroformate groups proved that the other PT‐catalysts were less efficient under the given reaction conditions.MALDI‐TOF mass spectrum of the polycarbonate No. 3b.magnified imageMALDI‐TOF mass spectrum of the polycarbonate No. 3b.

Macrocycles, 22

AbstractThe phosgenation of bisphenol A with diphosgene in the CH2Cl2/NaOH system was studied using the pseudo‐high‐dilution method either with triethylamine, with triethylbenzyl ammonium chloride (TEBA‐Cl), or with tetraphenylphosphonium chloride as catalyst. For Ph4PCl, only low‐molecular‐weight polycarbonates containing various by‐products were obtained. With the TEBA catalyst, the fraction of cycles and the average molecular weights increased with higher feed ratios of the catalyst. Both the fraction of cycles and the molecular weights steeply decreased at higher temperatures. With triethylamine as catalyst both the fraction of cycles and molecular weight passed through a maximum at low catalyst concentration, when the feed ratio of triethylamine was varied. Higher temperatures favored slightly lower fractions of cycles and lower molecular weights. Samples containing ≥ 95 mol‐% of cycles were obtained. The cycles were identified by matrix‐assisted laser desorption ionization time‐of‐flight (MALDI‐TOF) mass spectrometry up to 22 000 Da in the case of virgin samples, and up to 55 000 Da after fractionation by size exclusion chromatography (SEC). Selected samples were characterized by SEC measurements and evaluated by the triple‐detection method. High polydispersities and a tendency towards a bimodal mass distribution were found, when triethylamine was used as catalyst.MALDI‐TOF mass spectrum of a polycarbonate prepared by triethylamine‐catalyzed phosgenation at 20 °C by the pseudo‐high‐dilution method.magnified imageMALDI‐TOF mass spectrum of a polycarbonate prepared by triethylamine‐catalyzed phosgenation at 20 °C by the pseudo‐high‐dilution method.

A Facile Synthesis of Phenylacetic Acids via Willgerodt—Kindler Reaction under PTC Condition.

Abstract Phenylacetic acids are efficiently synthesized from acetophenones via thiomorpholides under Phase Transfer Catalytic (PTC) condition. The reaction proceeds efficiently by using triethyl benzyl ammonium chloride (TEBA) as PTC and the reaction time decreased dramatically upto 1/5th (24–5) to afford pure products in good to excellent yield.

A Facile Synthesis of Phenylacetic Acids via Willgerodt-Kindler Reaction Under PTC Condition

Phenylacetic acids are efficiently synthesized from acetophenones via thiomorpholides under Phase Transfer Catalytic (PTC) condition. The reaction proceeds efficiently by using triethyl benzyl ammonium chloride (TEBA) as PTC and the reaction time decreased dramatically upto 1/5th (24–5) to afford pure products in good to excellent yield.

Kinetics of copper electrodeposition in the presence of triethyl-benzyl ammonium chloride

Quasi-steady state hydrodynamic voltammetry at a rotating-disc electrode and electrochemical impedance spectroscopy were used to investigate the influence of triethyl-benzyl-ammonium (TEBA) chloride on the kinetics of copper electrodeposition from sulphate acidic electrolytes. SEM and X-ray diffraction analysis were used to examine the morphology and the structure of copper deposits. The kinetic parameters (i 0, α c, k 0), obtained by both Tafel and Koutecky–Levich interpretations lead to the conclusion that TEBA acts as an inhibitor of copper electrodeposition process, as a consequence of its adsorption on the electrode surface. The influence of TEBA on the kinetics of copper electrodeposition was explained in terms of a reaction model confirmed by the simulated impedance spectra. TEBA acts only as a blocking agent competing for adsorption active sites of the cathodic surface with cuprous ions without changing the reaction pathway corresponding to the absence of the additive.