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The prospects of using cerium as a modifying additive of Mg–Al hydrotalcite-derived oxide system have been estimated by low-temperature nitrogen ad(de)sorption, X-ray diffraction, scanning electron microscopy, 1H and 27Al solid-state nuclear magnetic resonance (NMR), X-ray photoelectron and UV–Vis diffuse reflectance spectroscopy techniques. The effect of such tuning of structural-textural characteristics and acid–base properties of the surface on its catalytic performance in ethanol conversion has been studied. Solid-state NMR spectroscopic study of the probe molecule adsorption and temperature-programmed desorption of NH3 and CO2 with mass-spectrometry control are used to determine the nature and strength distribution of acidic and basic sites of Mg–Al(–Ce) oxide systems. It has been found that the selectivity towards 1-butanol up to 68.1% (548 K) is achieved in ethanol conversion over Mg–Al–Ce sample at time-on-stream ≤ 2 h. At higher time-on-stream, the specific rates of the target product (1-butanol) formation are comparable for both modified and un-modified catalysts, but the products distribution differs. Cerium modification of Mg–Al oxide catalyst leads to increase in specific rate of acetaldehyde formation due to increase in the number of basic sites and their surface density. Wherein, the rate of ethanol dehydration products (ethylene and diethyl ether) is reduced, apparently, due to decrease in a number of Lewis acidic sites formed by Al3+ cations octahedrally coordinated to oxygen.

The reaction of SrBr2 with 2 equiv of sodium N,N-dimethylaminodiboranate (DMADB; Na(H3BNMe2BH3)) in Et2O at 0 °C followed by crystallization and drying under vacuum gives the unsolvated strontium compound Sr(H3BNMe2BH3)2 (1). Before the vacuum-drying step, the colorless crystals obtained by crystallization consist of the diethyl ether adduct Sr(H3BNMe2BH3)2(Et2O)2 (2). If the reaction of SrBr2 with 2 equiv of Na(H3BNMe2BH3) is carried out in the more strongly coordinating solvent thf, the solvate Sr(H3BNMe2BH3)2(thf)3 (3) is obtained. Treating the thf adduct 3 with 1,2-dimethoxyethane (dme), bis(2-methoxyethyl) ether (diglyme), or N,N,N',N'-tetramethylethylenediamine (tmeda) in thf affords the new compounds Sr(H3BNMe2BH3)2(dme)2 (4), Sr(H3BNMe2BH3)2(diglyme) (5), and Sr(H3BNMe2BH3)2(tmeda) (6), respectively, in greater than 60% yields. Treatment of 3 with 2 equiv of the crown ether 12-crown-4 affords the charge-separated salt [Sr(H3BNMe2BH3)(12-crown-4)2][H3BNMe2BH3] (7). Crystal structures of all the Lewis base adducts are described. Compounds 2-6 all possess chelating κ2-BH3NMe2BH3-κ2 groups, in which two hydrogen atoms on each boron center are bound to strontium. Compound 6 is dinuclear because each metal atom is also coordinated to one hydrogen atom on a BH3NMe2BH3- ligand that chelates to the neighboring metal center. Compound 7 possesses an unusual κ1-BH3NMe2BH3- group owing to the near-complete encapsulation of the Sr atom by two 12-crown-4 molecules; the other BH3NMe2BH3- anion is a charge-separated counterion. When they are heated, the diglyme and tmeda compounds 5 and 6 melt without decomposition and can be sublimed readily under reduced pressure (1 Torr) at 120 °C. The diglyme and tmeda adducts are some of the most volatile strontium compounds known and are promising candidates as CVD precursors for the growth of strontium-containing thin films.

In this article, we investigated the I2-promoted cyclic dialkyl ether formation from 6-membered oxanickelacycles originally reported by Hillhouse. A detailed mechanistic investigation based on spectroscopic and crystallographic analysis revealed that a putative reductive elimination to forge C(sp3)–OC(sp3) using I2 might not be operative. We isolated a paramagnetic bimetallic NiIII intermediate featuring a unique Ni2(OR)2 (OR = alkoxide) diamond-like core complemented by a μ-iodo bridge between the two Ni centers, which remains stable at low temperatures, thus permitting its characterization by NMR, EPR, X-ray, and HRMS. At higher temperatures (>−10 °C), such bimetallic intermediate thermally decomposes to afford large amounts of elimination products together with iodoalkanols. Observation of the latter suggests that a C(sp3)–I bond reductive elimination occurs preferentially to any other challenging C–O bond reductive elimination. Formation of cyclized THF rings is then believed to occur through cyclization of an alcohol/alkoxide to the recently forged C(sp3)–I bond. The results of this article indicate that the use of F+ oxidants permits the challenging C(sp3)–OC(sp3) bond formation at a high-valent nickel center to proceed in good yields while minimizing deleterious elimination reactions. Preliminary investigations suggest the involvement of a high-valent bimetallic NiIII intermediate which rapidly extrudes the C–O bond product at remarkably low temperatures. The new set of conditions permitted the elusive synthesis of diethyl ether through reductive elimination, a remarkable feature currently beyond the scope of Ni.

Synthesis of monomers is the key and most labor-consuming step in the development of highly selective membrane materials. Polyalkylenesiloxanes show promise for separation of vapors of organic components from gas mixtures. The paper considers two approaches to the synthesis of 1,1,3,3,5,5-hexamethyl-2-oxa-1,3,5-trisilacyclohexane, a monomer for preparing poly-bis(dimethylsilmethylene)dimethylsiloxane, a promising polymer material for gas-separation and pervaporation membranes. Modified synthesis procedures using both approaches, closure of the six-membered ring via formation of the Si–O–Si or Si–C bond, are suggested. Comparative analysis shows that, among organomagnesium cyclization methods, the one-step method in a diethyl ether or diethyl glycol dibutyl ether should be preferred. The suggested procedure allows reaching the monomer yield as high as 75–80% and more.

In this research, a one-pot production of biodiesel, hydrocarbons, oxygenates, and aromatics form Chlorella vulgaris was performed in supercritical methanol without catalyst and in the presence of TiO2 and SrTiO3 nanocatalysts. The reaction in the presence of SrTiO3 showed the highest production yield of fatty acid methyl esters (FAMEs). The co-solvents water, chloroform, diethyl ether, and n-hexane were used for modifying the supercritical medium to affect the product yields in SrTiO3-catalyzed process. The SrTiO3 nanocatalyst was photochemically prepared and the leaching of catalysts into the products was evaluated. Results showed that for all products except oxygenates, the addition of diethyl ether and chloroform to methanol had a slightly positive effect on the production yields. For all products, n-hexane co-solvent showed the best performance with production yields of 16.65, 2.42, 2.12, and 0.57 mg.g−1biomass for FAMEs, oxygenates, hydrocarbons, and aromatics, respectively. Furthermore, the water showed no significant effect on production yields except in the case of oxygenates. The results may be due to the high ability of n-hexane for dissolving the biomass in the reaction condition. Also, the ICP-OES detected no trace amounts of catalyst in the final product and it confirms that the photochemical method for catalyst preparation can prevent the catalyst leaching.

The deprotonation of 3-aryl-substituted alkyl propargyl ethers with n-butyllithium provides an ambident anion that reacts with carbonyl compounds to provide mixtures of γ-substituted products with alkoxyallene substructure and of α-substituted propargyl ethers. The ratio of the two product types strongly depends on the solvent: in diethyl ether the γ-substituted products predominate whereas the more polar tetrahydrofuran favors the α-adducts. The primary addition products undergo 5-endo-trig or 5-endo-dig cyclizations under various reaction conditions to afford isomeric furan derivatives. The highest selectivity in favor of α-substituted products was achieved by employing a MOM-protected propargyl ether. During the protonation step no evidence for a proton shift leading to an isomeric allenyl anion was found. A brief mechanistic discussion tries to rationalize the observed regio­selectivities.

The relative in vitro and in vivo evaluation of two hydroxychloroquine (HCQ) products was conducted. In vitro studies involved assay, content uniformity and dissolution test, and a two-way crossover fashion were used for in vivo studies. Blood samples were collected at appropriate intervals and HCQ levels were measured using a validated reversed-phase high-performance liquid chromatography (HPLC) method. The drug and the internal standard, chloroquine (CQ), were extracted from blood with diethyl ether, separated and dried under nitrogen gas. Residues were reconstituted in the mobile phase and analyzed at 340 nm on a μ-bondapack C18 (250 × 4.6 mm) HPLC column with acetonitrile:methanol:KH2PO4 (10:10:80) mixture containing 0.01% triethylamine. The standard curve was linear within 50–1,500 ng/mL HCQ (R2 = 0.9996), relative errors were 1.6 to 5%, and the CV% ranged from 7 to 15.4. The resolution factor and RSD were 1.62 and 0.35% and in vitro data of both products met the USP requirements. The 90% confidence intervals for the ratios of the AUC0–96, Cmax and Tmax and their corresponding logarithmically transformed values of generic product over those of Plaquenil® were within the acceptable limit of 0.80–1.20 and 0.80–1.25, respectively. Therefore, the generic HCQ was bioequivalent to the innovator formulation.

The reaction of hexaphenyl-carbodiphosphorane (1) with equi- or twice-molar amounts of PhLi or n-BuLi in diethyl ether is leading selectively to dilithio-carbodiphosphorane (3). Under optimized con...

The present research work primarily focuses on the extraction of mango seed biodiesel from the waste mango seeds through transesterification process. Preliminary tests were conducted with diesel an...

Efficient and reliable synthesis of substituted hydrazinylpyridines in thick-wall ACE tubes via nucleophilic substitution of a chlorine substituent in different chloropyridines is presented. Hydrazine hydrate and alkylhydrazines were used as nucleophiles and simple alcohols and diethyl ether were the only organic solvents necessary, making the process environmentally and user friendly, potentially reaching 100% atomic efficiency. In the next step, transformations of succinic anhydride moieties fused to the bicyclo[2.2.2]octene framework into succinimide moieties via nucleophilic substitution of oxygens were conducted. As nucleophiles two of the synthesized hydrazinylpyridines (2-hydrazinyl-3-nitropyridine and 2-hydrazinyl-5-nitropyridine) and also hydrazine hydrate, phenylhydrazine, and 4-nitrophenylhydrazine were used. Reactions were again carried out in ACE tubes and only simple alcohols, diethyl ether, and acetone were needed as solvents. One of the prepared bicyclo[2.2.2]octene adducts displayed water solubility thus being a promising candidate for future studies as a novel bidentate ligand for various metal cations in aqueous solutions or acting as an unprecedented halogen bond acceptor.

In this investigation, chromatographic separations of the diethyl ether extracts of two European annual Bupleurum taxa, B. praealtum and B. veronense, yielded nine new natural products, namely, a series of esters of stereoisomeric tetradeca-5,7,9,11-tetraen-1-ols (1-4 and 8), a tetra-unsaturated γ-tetradecalactone (5), a dibenzylbutyrolactone lignan (7-oxoarcitin, 6), a falcarinol-related 17-membered macrolide (7) possessing a conjugated diyne-system, and an acylphloroglucinol derivative (9). All these new compounds were fully characterized by NMR, IR, UV, MS, and optical rotation measurement, including 1H NMR full spin spectral simulation, whereas the absolute configurations of 1, 5, and 9 were determined via chemical correlations and NMR analysis of Mosher esters. The in vitro potential immunomodulatory activities of 1, 4, 5, and (+)-arcitin were assessed by determining their effects on the functional properties of isolated rat splenocytes and peritoneal macrophages. The results obtained support the known immunomodulatory ethnomedicinal usage of Bupleurum species.

Hydrothermal treatment for dairy manure into value-added hydrochar and bio-oil is a potential technology for its resource utilization. During the process of treatment, extractant is applied to the separation of hydrochar and bio-oil. In this study, three polar extractants (ethyl acetate, dichloromethane, diethyl ether) and two nonpolar extractants (n-hexane and petroleum ether) were used, and the physico-chemical properties of hydrochar and the composition of bio-oil were investigated. Compared with nonpolar extractants, polar extractants could extract the bio-oil absorbed on the hydrochar exterior and interior surface, resulting in more mass loss of hydrochar and better extraction performance on the production of bio-oil. The decrease of H/C atomic ratio and the increase of O/C atomic ratio indicated the demethanation tendency to occur during the extraction process, and enhanced the hydrochar stability. The scanning electron microscope and specific surface area analysis revealed that polar extractant had a more positive effect than nonpolar extractant on the occurrence of disperse spherical microparticles and the augment of hydrochar specific surface area. The bio-oil from polar extractant mainly consisted of N-containing compounds, ketones, phenols and acids, while the bio-oil from nonpolar extractant mainly consisted of esters, alkanes and aromatics. These results reveal that the hydrochar extracted by polar solvent exerts a greater potential for the production of carbon-based material.

The reaction of 2-methoxy-5-chlorophenyllithium with SbCl3 (3 : 1) in diethyl ether has afforded tris(2-methoxy-5-chlorophenyl)antimony, which has been crystallized from benzene as solvate. Treatment of the solvate with bromine in chloroform has led to the formation of tris(2-methoxy-5-chlorophenyl)antimony dibromide, which has been isolated from benzene as solvate as well. The product of a similar reaction with chlorine, tris(2-methoxy-5-chlorophenyl)antimony dichloride, has been also obtained via oxidation of tris(2-methoxy-5-chlorophenyl)antimony with copper dichloride in acetone. The structural features of the obtained compounds have been established by means of single-crystal X-ray diffraction analysis.

Breast cancer is among the frequently occurring cancer worldwide. The foremost underline aim of this study was to determine the growth inhibitory effect along with mechanistic study of a Bruguiera gymnorrhiza extract on MCF-7. The cytotoxicity activity was determined by using the MTS assay. Butanol extract exhibited the maximum cytotoxicity activity against the MCF-7 cells with IC50 of 3.39 μg/mL, followed by diethyl ether and methanol extract (IC50 at 16.22 μg/mL and 37.15 μg/mL, respectively) at 72 h. The DeadEndTM Colorimetric Apoptosis Detection System confirmed the induction of apoptosis (via DNA fragmentation) in MCF-7 cells. Both butanol and diethyl ether extracts of B. gymnorrhiza significantly increase the caspase-3 level. However, the diethyl ether extract induced higher caspase-9 levels compared to caspase-8, suggesting that the intrinsic pathway was the major route in the process of apoptosis. Thin-layer chromatography profiling demonstrated the presence of phenolic, terpene, and alkaloid compounds in crude methanol, diethyl ether, and butanol extracts. The phytochemicals present in the extracts of B. gymnorrhiza might have the potential to be a future therapeutic agent against breast cancer.

Linear and networked poly(ionic liquid)s, which were composed of polyoxetanes and imidazolium groups, were synthesized by cationic polymerization of mono- and di- functional oxetanyl monomers, and the properties of the obtained polymers were investigated. The monofunctional monomer, 3-(3-ethyl-3-oxetanylmethyl)-1,2-dimethylimidazolium bis(trifluoromethanesulfonyl)imide (OXDMImTFSI), was prepared from the reaction of 3-ethyl-3-oxetanylmethyl chloride with 1,2-dimethylimidazole followed by exchanging the chloride to bis(trifluonomethanesulfonyl)imide (TFSI). The difunctional monomer, 1,3-di(3-ethyl-3-oxetanylmethyl)-2-methylimidazolium bis(trifluoromethanesulfonyl)imide (DOXMImTFSI), was prepared from the reaction of 3-ethyl-3-oxetanylmethyl chloride with 2-methylimidazole and successive ion-exchange of chloride to TFSI. OXDMImTFSI was polymerized by addition of a catalytic amount of BF3 diethyl ether complex. The obtained linear polyOXDMImTFSI showed good stability toward heat and basic conditions. Networked polymer films were prepared by homo/co-polymerization of DOXMImTFSI or DOXMImTFSI/OXDMImTFSI liquid layers using the thermally latent cationic initiator, (1-naphthylmethyl) methyl p-hydroxyphenyl sulfonium hexafluoroantimonate (SI-60). The obtained films showed good ion-exchange ability between TFSI, Cl, and OH anions.

Contentions still exist as to the most humane method of sacrificing experimental animals. Beyond humaneness, there is also the issue of appropriateness of a method of sacrifice with regards to organ safety. This study compared four common methods of rodent sacrifice used in Nigeria and their effects on the brain. Twenty male Wistar rats weighing 150 to 180g were randomly separated into four groups of five rats each. After a two week period of acclimatization, the animals were sacrificed; Group A by Cervical dislocation (CD) which also served as control, Group B by chloroform inhalation (CI), Group C by diethyl ether inhalation (DEI) and group D by Formalin inhalation (FI). The time taken for the animals to pass out was documented and the brains were harvested. Four of the brains from rats in each group were homogenized in phosphate buffer solution and centrifuged at 10000rpm. The supernatant were used for antioxidant studies. The remaining one brain from each group were fixed in 10% formal saline and after 48 hours, the cerebellum (CB) and hippocampus (Hp) were used for histological studies using the H & E method. Our results show although CD was the quickest, it gave the least quantity of blood. Meanwhile CI was the most humane, gave the most blood and saved time compared to DEI and FI. None of the methods of sacrifice showed adverse effect on the antioxidant parameters of the rats. However, histological studies showed that while CD and CI showed no adverse effects on the hippocampus, only CD was completely safe for the CB. The other methods showed various levels of cell death. It is therefore expedient to consider these factors in making the choice of an appropriate method of sacrifice and to use the most humane and safest method with reference to the organ studied.

First reported in 1930, MoCl3O(Et2O)2 is a by-product of the reductive synthesis of MoCl4(OEt2)2 from MoCl5. We report herein the X-ray crystal structure and Hirshfeld surface characteristics of mer-MoCl3O(Et2O)2, or [MoCl3O(C4H10O)2]. The compound crystallizes in the orthorhombic space group P212121. The molybdenyl (Mo=O) bond length is 1.694 (3) Å and the cis- and trans-Mo—O distances are 2.157 (3) and 2.304 (3) Å, respectively. Intermolecular Mo=O...H bonding is present in the lattice, with the shortest distance being 2.572 Å.

The paper is devoted to the development of diethyl ether + hexane + ethyl acetate + ethanol mixture (solvents of the dihydroquercetine production) separation flowsheets based on the analysis of the structure of the phase diagram. The phase equilibrium of the quaternary system was studied using mathematical modeling in the AspenPlus. The parameters of Non Random Two Liquid model allow reproducing vapor-liquid equilibrium data and azeotropes characteristics with a relative error not exceeding 5%. It was shown that the system was characterized by the presence of three binary azeotropes and the phase diagram was divided into three distillation regions. Based on a literature analysis N-methyl-2-pyrrolidone was selected as a solvent for the extractive distillation. The selectivity of the separating agent was calculated and it was shown that N-methyl-2-pyrrolidone influenced the relative volatility of components to varying degrees. Two flowsheets containing a diethyl ether separation column and two extractive distillation complexes were proposed. The flowsheets differ in the sequence of separation of the components: hexane, ethyl acetate and ethanol. The distillation process was simulated and the operating column parameters (number of stages, feed stage, reflux ratio, solvent to feed volume ratio) were determined. Selected parameters meet the minimum energy consumption. An energy-efficient separation variant was chosen.

Densities of pure liquids and binary mixtures of diethyl ether (DEE) with 2-alkoxyethanols (2- methoxyethanol, 2-ethoxyethanol and 2-butoxyethanol) have been determined over the entire range of solvent compositions at (293.15, 298.15 and 303.15) K. Excess molar volumes (VM E ) have been calculated from the density data and were fitted into the Redlich-Kister type polynomial equation to obtain the fitting parameters Ai. The values of excess molar volumes, vm E were negative in regions of low diethyl ether (DEE) composition and small positive values were observed in regions of high diethyl ether (DEE) compositions in all the systems studied. VM E values were also found to decrease with increase in temperature and increase in chain length of the 2-alkoxyethanols. The above trends were attributed to the combined effects of disruption and formation of hydrogen bonds between like molecules of 2- alkoxyethanols and unlike molecules of diethyl ether (DEE), respectively.

In the present work, mechanistic pathways and kinetics of catalytic dehydration of ethanol were investigated in a closed batch reactor for the formation of diethyl ether, and ethylene over the synthesized NiO loaded HZSM-5 in the range of 160–240 °C. The effect of the presence of water on reaction performance was also evaluated. No significant negative impact of water over diethyl ether yield was observed up to 1:1 ethanol–water molar ratio. The proposed two-step kinetic model highlights the mechanistically essential comparison between the strong (Bronsted) and weak (Lewis) acid sites of catalyst for ethanol conversion to diethyl ether. Intramolecular dehydration of ethanol over strong acid sites led to ethylene formation. Enhancement of weak acid sites due to NiO loading over HZSM-5 led to interestingly higher yields of diethyl ether by a combination of ethylene and ethanol. Optimal consideration for maximum conversions was observed with high reusability. Graphical abstract for ethanol dehydration on Ni-HZSM-5 catalyst.

The present experimental investigation is conducted to examine the working characteristics of compression ignition (CI) engine using oxygenated additives such as diethyl ether and ethanol to the blends of Calophyllum inophyllum biodiesel. Experiments are conducted on a water-cooled single-cylinder constant speed DI (direct injection) diesel engine under same operating circumstances. The results indicates that an enhancement of brake thermal efficiency is up to 3.7% and 6.2% with an addition of ethanol and DEE additive in biodiesel blended fuels respectively at maximum load condition. This is attributable to the existence of higher oxygen value and volatile nature of the additives. The combustion characteristics like in-cylinder pressure and net heat release rate of DEE blended fuels are 1.1-5.2% and 0.4-2.7% higher than other blends respectively. This is mainly due to higher cetane number and high volatile nature of DEE. This also results in higher NOX emissions. But 2-9% drop in nitrous oxide emission is noticed for biodiesel with ethanol blends compared to all other blends. This is as a result of superior latent heat of vaporization and lesser cetane number of ethanol which results in lower cylinder pressure about 0.4-2.6% and this end up with more unburned HC and CO emissions. Energy and exergy studies help to analyze the result of ethanol and DEE additive along with blends of biodiesel. The exergy efficiencies of DEE blended fuels enhance up to 2.3-6% compared to other blends at all load conditions. This is attributable to the superior combustion characteristics of DEE.

Ethanol dehydration to ethene via direct and ether mediated paths is mechanistically investigated via transient experiments in a Temporal analysis of products, TAP-3E reactor over a temperature range of 473–573 K in Knudsen regime conditions. Pulse experiments of ethanol over H-ZSM-5 do not yield diethyl ether as a gas phase product. Cofeed experiments with diethyl ether and C-13 labeled ethanol show that ethene formation from diethyl ether is the preferential route. Kinetic parameters from ab initio based microkinetic modelling of ethanol dehydration are compared to the experimental data of the TAP reactor by an in-house developed reactor model code TAPFIT. Rate coefficients in ethene adsorption are in agreement with the ab initio based microkinetic modelling parameters. The experimental data from a diethyl ether feed are compared to the simulated responses from the ab initio based kinetic parameters and further optimized by regression analysis. Reaction path analysis with the optimized kinetic parameters identifies the preference of an ether mediated path under the applied transient experimental conditions.

Mono- and diacylglycerol (MAG and DAG) emulsifiers (E 471) are widely applied to regulate techno-functional properties in different food categories, for example, in dairy products. A method for the determination of MAG and DAG in aerosol whipping cream by high-performance thin-layer chromatography with fluorescence detection (HPTLC–FLD) after derivatization with primuline was developed. For sample preparation, aerosol whipping cream was mixed with ethanol, followed by the addition of water and liquid-liquid extraction with tert-butyl methyl ether. The sample extracts were analyzed by HPTLC–FLD on silica gel LiChrospher plates with n-pentane/n-hexane/diethyl ether (22.5:22.5:55, v/v/v) as mobile phase, when interfering matrix like cholesterol and triacylglycerols were successfully separated from the E 471 food additives. For quantitation, an emulsifier with known composition was used as calibration standard and the fluorescent MAG and DAG were scanned at 366/> 400 nm. Limits of detection and quantitation of 4 and 11 mg/100 g aerosol whipping cream were obtained for both monostearin and 1,2-distearin, respectively, and allowed the reliable quantitation of MAG and DAG from E 471 far below commonly applied emulsifier amounts. Recoveries from model aerosol whipping cream with 400 mg E 471/100 g were determined in a calibration range of 200–600 mg E 471/100 g sample and ranged between 86 and 105% with relative standard deviations below 7%. In aerosol whipping creams from the German market, E 471 amounts ranged between 384 and 610 mg/100 g. Electronic supplementary material The online version of this article (10.1007/s00216-020-02876-2) contains supplementary material, which is available to authorized users.

Mid-infrared spectra for C-D···O hydrogen (H)-bonded binary complexes of CDCl3 with acetone (AC), cyclohexanone (CHN), diethyl ether (DEE), and tetrahydrofuran (THF) have been measured in the vapor phase at room temperature and in an argon matrix at 8 K. Remarkable matrix effect has been observed in each case with respect to the spectral shift of the donor group's stretching fundamental (ΔνC-D). In the case of complexes with AC and CHN, the sign of ΔνC-D changes from a few wavenumbers positive (blue shift) in the vapor phase to a few tens of wavenumbers negative (red shift) in the argon matrix. For the two ether complexes, although no apparent reversal in the sign of ΔνC-D occurs, but the magnitudes of the red shifts in the matrix are manifold larger, and the bands appear with large enhancement in transition intensity. The medium effect has been explained consistently in terms of the local hyperconjugative charge transfer interaction at the H-bonding sites of the complexes and its interplay with the H-bond distance that varies with the physical conditions of the medium. Under the matrix isolation condition, νC-D bands of CHN and THF complexes depict a large number of substructures, which has been interpreted in terms of matrix site effect as well as Fermi resonance enhancement of the fingerprint combination tones and trapping of more than one isomer of the complexes in the matrix sites.

The catalytic conversion of ethanol to butanol and butadiene at 633 K and atmospheric pressure (7 vol% ethanol) was studied over calcium phosphate materials pretreated over a wide temperature range. For calcium phosphate pretreated at or below 923 K, the resulting solid had an apatite structure identified by X-ray diffraction and strong acid sites probed by triethylamine (TEA) adsorption microcalorimetry. The low temperature pretreated materials were not effective at ethanol coupling reactions but instead were highly selective to acid-catalyzed products ethene and diethyl ether. Pretreatment of calcium phosphate at 973 K transformed the apatite structure to β-tricalcium phosphate, which exposed both acid and base sites evaluated by TEA and CO2 adsorption microcalorimetry. High temperature pretreated calcium phosphate catalysts formed the coupling products butanol and butadiene during ethanol reaction. The butadiene selectivity was improved by supporting calcium phosphate on zirconia. The influence of catalyst structure on the activity and selectivity of calcium phosphates was elucidated for the conversion of ethanol.

The isolation triterpenoid from Nyamplung (Callophyllum inophyllum, Linn.) leaves has been conducted. The isolation was employed by maceration using ethanol as solvent and liquids extraction using ethyl acetate. Ethyl acetate extract was partitioned successively using nonpolar solvent with hexane, dichloromethane, and diethyl ether, respectively. The diethyl ether extract was purified by column chromatography. The isolated compound of fraction D1 was obtained as white solids crystal with yield of 0.0035%. The isolated compound was determined based on the FTIR, 1HNMR, 13CNMR, HSQC, and HMBC spectra. The isolated compound was identified as 28-hydroxy-3-friedelanone.

Processes of the low-temperature enzymatic synthesis of esters in nonaqueous media of organic solvents with participation of heterogeneous biocatalysts synthesized by the adsorption immobilization of a recombinant lipase from Thermomyces lanuginosus (Pichia pastoris producer) on macroporous carbon aerogel were investigated. The esterification reaction was conducted using individual organic solvents of different polarity, such as nonpolar ones (lоgP > 2.5) – hexadecane, hexane and toluene, and polar solvents (lоgP < 1) – diethyl ether, tert-butanol and acetone, as well as their binary mixtures of different composition, for example, a mixture of hexane with diethyl ether having the composition 1 : (1/5÷3, vol. fr.). The effect of the solvent and co-solvent nature on the properties of synthesized biocatalysts, namely the enzymatic activity and operational stability, was studied in the batch esterification of heptanoic acid (C7:0) by alcohols, particularly the polar substrates – ethanol and n-butanol, or nonpolar alcohols – n-octanol and n-hexadecanol. Activity of the synthesized biocatalysts was found to depend to a great extent on polarity of both the solvents used in the reaction and the alcohol substrates. The maximum activity of 400 EA·g–1 was observed in a medium of nonpolar and nonviscous hexane (lоgP = 2.9), whereas the minimum activity of 4 EA·g–1 – in acetone (lоgP = 0.4); esterification of heptanoic acid in the presence of tert-butanol (lоgP = 0.6) virtually did not proceed. The activity of biocatalysts was shown to depend nonmonotonically on the lоgP value of individual solvent. In the binary mixtures of organic solvents, such as hexane/diethyl ether, biocatalytic activity linearly increased with an increase in lоgPmixture; in addition, biocatalysts exhibited the maximum operational stability.

Sonochemically mediated dehydrogenation of in situ generated complex metal hydrides is a promising methodology for the synthesis of mixed-metal powders for fuel applications that can be tailored toward greater energy content and other desirable characteristics. Here, we report a significant improvement in the synthesis of Ti–Al–B reactive metal powders by the elimination of parasitic impurities from the synthesis, focusing on the effects of synthetic and processing parameters on the final fuel composition, morphology, energy content, and reactivity. Reactions to produce fuel samples were carried out using both the previously reported addition of ethereal solutions of LiAlH4 and LiBH4 to a solution of TiCl4 and, importantly, the reverse, where a homogeneous solution of TiCl4 in diethyl ether was added to a homogeneous solution of LiAlH4 and LiBH4. The product powders were characterized via TGA/DSC, XPS, ICP-OES of the digestate, and oxygen bomb calorimetry of polymer-encased metal powder–fuel composites. In order to accurately measure the energy content of these materials, HTPB was used as a protective matrix for powders combusted using bomb calorimetry. The powders produced by the two methods had similar elemental compositions; however, the materials produced by “reverse addition” exhibited surprisingly different morphology and fuel properties compared to the “traditional” counterparts. The improvements in synthetic methodology lead to significant improvements in the fuel energy content, remarkable particle size monodispersity in the submicron size regime, and excellent reproducibility of the energy release observed for powder fuel-HTPB composites.

From last two decades, research in the field of alternative, clean and renewable bio-fuels has been increased dramatically for performance improvement, emission control, and running cost reduction ...

Diethyl ether (DEE) has been proposed as a biofuel additive for compression-ignition engines, as an ignition improver for homogeneous charge compression ignition (HCCI) engines, and as a suitable component for dual-fuel mixtures in reactivity-controlled compression ignition (RCCI) engines. The combustion in these engines is significantly controlled by low-temperature (LT) chemistry. Fundamental studies of DEE LT oxidation chemistry and of its influence in fuel-mixture oxidation are thus highly important, especially at elevated pressures. Elevated pressure speciation data were measured for the LT oxidation of DEE, of its similarly-structured linear five-heavy-atom hydrocarbon fuel (n-pentane), and of a mixture of the two fuels in a jet-stirred reactor (JSR) in the temperature range of 400–1100 K and at various pressures up to 10 bar. The pressure influence on the LT oxidation chemistry of DEE was investigated by a comparison of the measured profiles of oxidation products. The results for DEE and n-pentane were then inspected with regard to fuel structure influences on the LT oxidation behavior. The new speciation data were used to test recent kinetic models for these fuels [Tran et al., Proc. Combust. Inst. 37 (2019) 511 and Bugler et al., Proc. Combust. Inst. 36 (2017) 441]. The models predict the major features of the LT chemistry of these fuels well and could thus subsequently assist in the data interpretation. Finally, the LT oxidation behavior of an equimolar mixture of the two fuels was explored. The interaction between the two fuels and the effects of the pressure on the fuel mixture oxidation were examined. In addition to reactions within the combined model for the two fuels, about 80 cross-reactions between primary reactive species generated from these two fuel molecules were added to explore their potential influences.

The solubility of benzanilide in sixteen pure organic solvents, including N, N-dimethylformamide, tetrahydrofuran, butanone, acetone, ethyl acetate, dichloromethane, n-butanol, diethyl ether, n-pro...

The aim of the present investigation is to examine the characteristics of diesel engine for varying concentrations of diethyl ether (DEE) as an oxygenated additive in repurpose used cooking oil (RU...

As an alternative fuel for the compression ignition engine, the biodiesel blended with diesel at low ratios is a widespread practice that alleviates exhaust emissions and aids in managing the fossi...

Antioxidants of natural origin which are based on agroprocessing waste appear as substance with high performance properties. They have complicated structure and contain a complex of biologically active compounds. This is why research of the above is particularly relevant in current competitive market. When working with plant raw materials and isolation of valuable compounds, the urgent issue is the choice of the method (extraction method) and extractant, which will ensure a maximum release of chemically active compounds. Known solvents such as methanol, ethanol, hexane, diethyl ether, and mixtures thereof are usually used for recovery. The purpose of this research was to study the effect of selected nonpolar solvents on the phytochemical composition and the antioxidant capacity of Prunus armeniaca L. Extracts were obtained using ethanol, silicone, propan-2-ol, and mixtures of ethanol silicone and propan-2-ol with silicone. In the obtained extracts, identification of the sequestered chemically active compounds was carried out by means of chromatography, mass spectrometry, and IR and UV spectrometry, and the extracts were evaluated on antioxidant properties. Various extracts showed varying degrees of antioxidant activity in various test systems, depending on the concentration. Since various antioxidant compounds have different mechanisms of action, several methods have been used to evaluate the effectiveness of antioxidant extracts. The results showed that the test solvents play an important role in the extraction of the plant material into the component composition, as well as the antioxidant ability of Prunus armeniaca L.

The present experiment deals with the study of addition of diethyl ether on the performance and emission characteristics of LHR engine using papaya methyl ester-eucalyptus oil blends. The test blen...