Category: esters-buliding-blocks

Peng, Qingrui published the artcileEffects of different ligand modifications on catalytic transfer hydrogenation of Lewis acid catalysts: Quantum chemical studies on the case of ZrCl2-Sal(ph)en, Computed Properties of 539-88-8, the main research area is electronic ligand modification catalytic transfer hydrogenation Lewis acid catalyst.

The systematic description of the steric and electronic ligand effects on the reactivity of the catalysts is one of the main goals in homogeneous catalysis. The experiments and mol. modeling calculations were performed to establish the structure-reactivity relationship with various ligand substituents of ZrCl2-Sal(ph)en-X (X = H, CH3, OCH3, Br, NO2, Cl). A clear linear free-energy relationship (LFER, r2=0.97/0.93) was found between Hammett σp value of the phenoxyl side group substituent X and the rate KX or reaction barrier of the hydrogenation of Et levulinate. Lewis acid sites are stronger in catalysts with an electron-withdrawing group close to the Zr site. In addition, the auxiliary ligands at two axial sites connected to the Zr site have a more significant impact on the catalyst activity. Among the three axial ligands (Cl, OH and OiPr), the -OH ligand with a smaller size endows addnl. basicity of catalyst, which is beneficial to the activation and dissociation of the hydroxyl group in the 2-propanol at the Lewis acidic sites (Zr4+) and basic sites(O2-), thus increasing the reaction rate of the Meerwein-Ponndorf-Verley (MPV)reaction of Et levulinate.

Journal of the Taiwan Institute of Chemical Engineers published new progress about Basicity, Lewis. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Computed Properties of 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Aitbelale, Rachid published the artcileEffects of 2-Butanol Addition on Waste Cooking Oil Biodiesel Density: An Updated Experimental Measurement and Thermodynamic Modeling Study, Application In Synthesis of 929-77-1, the main research area is butanol cooking oil biodiesel mixture density thermodn modeling EOS.

Biodiesels will become the most popular alternative energy resource to fossil diesels; they can be used alone or blended with an oxygenated additive in any proportion. The properties of biodiesels strongly depend on the type of the fatty acid Me esters (FAME) that compose them. The main objective of the present work is to study the influence of 2-butanol addition on the waste cooking oil biodiesel (WCOB), for this fact, the new exptl. d. data (952 points) of WCOB + 2-butanol binary mixtures over a wide range [seven compositions; 0 â‰?(WCOB) mole fraction x â‰?1] between 0.1 and 140 MPa and 298.15 and 393.15 K are presented. The exptl. data were correlated using Tait and perturbed chain-statistical associating fluid theory (PC-SAFT) equations of state (EoS), to the knowledge, this is the 1st time that d. measurements for the WCOB + 2-butanol mixture are correlated using the famous PC-SAFT EoS. The Tait equation predicts successfully the d. with a global absolute average deviation (AAD) of 0.089%, while the PC-SAFT model correlates well the d. with a very small global AAD of 0.223% in each composition Also, contrary to the Tait equation, the PC-SAFT model can explain some interactions between fluid mols. From the exptl. data, the excess volumes VE were calculated and fitted using the Redlich-Kister equation with a very small global standard deviation of 7.49 × 10-5 cm3/mol, and VE show a pos. and sym. parabolic shape in all composition ranges. Finally, the isobaric thermal expansivity, αp, and the isothermal compressibility, κT, were derived from the Tait equation and their observed trend was as expected.

Journal of Chemical & Engineering Data published new progress about Binary mixtures. 929-77-1 belongs to class esters-buliding-blocks, name is Methyl docosanoate, and the molecular formula is C23H46O2, Application In Synthesis of 929-77-1.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Rasulov, Suleiman M. published the artcilePpT and liquid-gas phase transition properties (PS,pS,TS) of binary n-hexane + methyl octanoate mixture near the critical point of pure n-hexane, Recommanded Product: Methyl octanoate, the main research area is hexane methyl octanoate binary mixture liquid gas phase transition.

PρT and phase transition properties (PS,ρS,TS) of the dilute binary mixture of n-hexane + Me octanoate have been studied near the critical point of pure n-hexane (solvent). The measurements were performed along 11 liquid, vapor and near-critical isochores between (39.3 and 621.1) kg·m-3 over a temperature range from (293 to 622) K at pressures up to 17.7 MPa for the fixed concentration of x = 0.088 mol fraction (or 0.05 mass fraction) of Me octanoate. The measurements were made using a constant-volume piezometer technique. The study was concentrated in the single – and two- phase regions near the critical point of pure n-hexane to precisely determine the phase boundary properties (PS,ρS,TS) and the critical property (PC,ρC,TC) data of the mixture The measured critical property data for the mixture were used to study of the isomorphic critical behavior of strongly singular properties such as isothermal compressibility KTX and isobaric heat capacity CPX along the critical isochore and the critical isotherm, i.e., Fisher renormalization (mixture-like behavior) of the critical exponent, -γγ/(1 – α), for strongly singular properties of mixture under study. The measured PρT data were also used to estimate the values of phys. meaningful (theor. important) parameters such as characteristic reduced temperature τ1and d. differences Δρ1 of the mixture We found that KTX and CPX of the studied mixture exhibit pure-like behavior along the critical isochore at temperature above 508.52 K (slightly above the critical temperature of pure n-hexane, 507.44 K) and along the critical isotherm at densities above 279.82 kg·m-3 (above the critical d. of pure n-hexane, 232.8 kg·m-3). The measured data were used to estimate the Krichevskii parameter Kkr,structural (Nexc)and volumetric (Vâˆ?) properties of the dilute mixture near the critical point of pure solvent (n-hexane).

Fluid Phase Equilibria published new progress about Binary mixtures. 111-11-5 belongs to class esters-buliding-blocks, name is Methyl octanoate, and the molecular formula is C9H18O2, Recommanded Product: Methyl octanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Rani, Manju published the artcileSolid-liquid equilibrium and kinematic viscosity of binary mixture of fatty acid alkyl esters, Quality Control of 110-42-9, the main research area is solid liquid equilibrium kinematic viscosity binary mixture fatty acid.

The separation and recovery of fatty acid alkyl esters (FAAE) is of great significance for various industries. Crystallization is a well-suited separation process for fatty acid mixtures which may be evolved by the understanding of solid-liquid equilibrium (SLE). The SLE and kinematic viscosity (v) at (T=298.15-318.15 K) and (P=0.1 mPa) for binary mixture of FAAE: Me decanoate (1)+ethyl decanoate or Me dodecanoate or Me tetradecanoate (2) has been studied. The deviation in kinematic viscosity (Δv) data was derived using exptl. v data. The measured SLE exhibit general single eutectic point like other organic mixtures The SLE data fit well with universal quasi-chem. (UNIQUAC) equation. The v values were interrelated using different equations recommended by Heric-Brewer, Krishnan-Ladda, and Lulian et al. Theor. estimated values using these empirical equations are in accordance with the exptl. values with percentage standard deviation less than 0.35. The v were also analyzed by means of the McAllister equation. The Δv data were also fitted with the Redlich-Kister polynomial equation. All three binary mixtures showed neg. Δv values.

Korean Journal of Chemical Engineering published new progress about Binary mixtures. 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Quality Control of 110-42-9.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Xiao, Zuobing published the artcileIdentification of key aromas of Chinese muskmelon and study of their formation mechanisms, Computed Properties of 111-11-5, the main research area is Chinese muskmelon formation mechanism key aroma identification.

The volatile compounds found in melons (Cucumis melo L.) obtained from three cultivars [Jiashi (JS), Xizhoumi17 (XZM) and Minqin (MQ)] were comprehensively analyzed by gas chromatog.-olfactometry (GC-O), gas chromatog.-mass spectrometry (GC-MS), and GC-flame photometric detection (GC-FPD). The result showed that 46, 45 and 69 volatile compounds were detected in XZM, JS and MQ samples by GC-MS, resp. Besides, 6, 8 and 9 sulfur compounds were detected by GC-FPD, resp. Di-Me sulfide, 1-propanethiol, 3-mercapto-3methylbutanol, 3-methyl-2-buten-1-thiol were detected for the first time in melon. 25 key aroma compounds were identified in MQ muskmelon by omission tests, among which (Z)-6-nonenal, (Z)-6-nonen-1-ol, 3-methylbutanal, 2-methylbutyl acetate, hexanal and Me thioacetate were particularly important. The interaction between three aroma compounds containing nine-carbon straight-chain structure and five thioesters in MQ muskmelon was studied by comparing their olfactory threshold and OAV values. Among the 18 binary mixtures, 8 mixtures showed a synergistic effect, 2 mixtures presented an additive effect, 2 mixtures showed no interaction, 6 mixtures exhibited a masking effect. There is a synergistic effect between (Z)-6-nonenal, (Z)-6-nonen-1-ol and (E, Z)-3,6-nonadien-1-ol, the aroma intensity of the mixture can be predicted by modified vector model.

European Food Research and Technology published new progress about Binary mixtures. 111-11-5 belongs to class esters-buliding-blocks, name is Methyl octanoate, and the molecular formula is C9H18O2, Computed Properties of 111-11-5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Xiao, Zuobing published the artcileIdentification of key aromas of Chinese muskmelon and study of their formation mechanisms, Synthetic Route of 140-11-4, the main research area is Chinese muskmelon formation mechanism key aroma identification.

The volatile compounds found in melons (Cucumis melo L.) obtained from three cultivars [Jiashi (JS), Xizhoumi17 (XZM) and Minqin (MQ)] were comprehensively analyzed by gas chromatog.-olfactometry (GC-O), gas chromatog.-mass spectrometry (GC-MS), and GC-flame photometric detection (GC-FPD). The result showed that 46, 45 and 69 volatile compounds were detected in XZM, JS and MQ samples by GC-MS, resp. Besides, 6, 8 and 9 sulfur compounds were detected by GC-FPD, resp. Di-Me sulfide, 1-propanethiol, 3-mercapto-3methylbutanol, 3-methyl-2-buten-1-thiol were detected for the first time in melon. 25 key aroma compounds were identified in MQ muskmelon by omission tests, among which (Z)-6-nonenal, (Z)-6-nonen-1-ol, 3-methylbutanal, 2-methylbutyl acetate, hexanal and Me thioacetate were particularly important. The interaction between three aroma compounds containing nine-carbon straight-chain structure and five thioesters in MQ muskmelon was studied by comparing their olfactory threshold and OAV values. Among the 18 binary mixtures, 8 mixtures showed a synergistic effect, 2 mixtures presented an additive effect, 2 mixtures showed no interaction, 6 mixtures exhibited a masking effect. There is a synergistic effect between (Z)-6-nonenal, (Z)-6-nonen-1-ol and (E, Z)-3,6-nonadien-1-ol, the aroma intensity of the mixture can be predicted by modified vector model.

European Food Research and Technology published new progress about Binary mixtures. 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Synthetic Route of 140-11-4.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zhou, Rusen published the artcilePower-to-chemicals: Low-temperature plasma for lignin depolymerisation in ethanol, Computed Properties of 5405-41-4, the main research area is lignin ethanol depolymerization low temperature plasma; Lignin depolymerisation; Low-temperature plasma; Renewable chemicals.

Lignin valorization into renewable fuels and platform chems. is desirable but still encounters major challenges due to lignin’s recalcitrant structure, and the lack of cost-, energy-, and material efficient conversion processes. Herein, we report a low-temperature plasma-based route to lignin depolymerization at mild conditions. The discharge over ethanol surface locally creating a high-energy and reactive environment rich in free electrons, energetic H radicals, and other reactive species, is well suited for lignin depolymerization Furthermore, assisted with a Fenton reaction (by adding Fe2O3 and H2O2) to sustain a more oxidative environment, the lignin conversion yield increases from 42.6% to 66.0%. Thus-obtained renewable chems. are rich in aromatics and dicarboxylic acid derivatives The proposed strategy on intensifying reactive chem. by high-power plasmas enables an effective power-to-chems. conversion of lignin and may provide useful guidelines for modern biorefineries.

Bioresource Technology published new progress about Depolymerization. 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, Computed Properties of 5405-41-4.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Osman, Che Puteh published the artcileDiscrimination of 11 Malaysian Durian Cultivars Based on Sulfur-Containing Volatiles and Esters Using Multivariate Data Analysis, Recommanded Product: Ethyl 3-hydroxybutanoate, the main research area is sulfur volatile ester Malaysian durian cultivar multivariate data analysis.

There are reports documenting the volatile oils of several durian cultivars in Malaysia. However, there is limited information on the rapid discrimination of the durian cultivars based on the composition of the total volatiles and individual volatile compounds Thus, the present work aims to discriminate 11 Malaysian durian cultivars based on their volatile compositions using multivariate data anal. Sulfur-containing volatiles are the major volatiles in D175 (Udang Merah), D88 (Darling), D13 (Golden Bun), DXO (D24 Special), D17 (Green Bamboo), D2 (Dato Nina), and D168 (Hajah Hasmah) durian cultivars, while esters are predominant in D99 (Kop Kecil), D24 (Bukit Merah), and D160 (Musang Queen) durian cultivars. D197 (Musang King) cultivar has an almost equal composition of sulfur-containing volatiles and esters. In the ester predominated volatile durian oil, Et 2-methylbutanoate and Pr 2-methylbutanoate are the major volatile compounds, while the durian cultivars with predominant sulfur-containing volatiles mainly contain di-Et disulfide, di-Et trisulfide, and 3,5-dimethyl-1,2,4-trithiolane. The durian cultivars were clustered into 8 clusters using principal component anal., with 3 clusters consisting of 2 cultivars, and with the remaining cultivars clustered individually. The highly sought-after durian cultivars, D160 and D197, were clustered into one. Hierarchal clustering anal. identified the distinct compounds which discriminate every durian cultivar.

Natural Product Communications published new progress about Durio zibethinus. 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, Recommanded Product: Ethyl 3-hydroxybutanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Owen, Rhodri N. published the artcileTowards a universal ion source: Glow Flow mass spectrometry, Application In Synthesis of 110-42-9, the main research area is ion source glow flow mass spectrometry.

A helium-microplasma ion source (Glow Flow) has been developed and characterised. It is engineered to be a simple design, of low-cost and can be readily retrofitted to most modern mass spectrometers. Initial assessment of its performance has shown it to be robust, reproducible and of high sensitivity. Glow Flow provides broad non-specific detection of samples from polar through to non-polar chemistries making it of wide utility. A study of persistent organic pollutants, polyaromatic hydrocarbons, low average-mol.-mass polymers (polyethyleneimine, polyethylene glycol, and polypropylene glycol) and a complex mixture of fatty-acid Me esters by direct sample introduction using a nebulised heated nitrogen flow was conducted. The ability to make quant. measurement was investigated using Me stearate and a linear calibration plot gave a R2 = 0.999 and limit-of-detection of �00 fmol. This design is extremely stable, in operation. Typical ions commonly observed are intense protonated mol. ions, radical mol. ions, hydride abstracted ions, and oxygen adduct ions. At present this system is valuable to apply to small mol. anal. (m/z < 1000), and is easily interfaced to gas and liquid chromatog., and likely to be useful for imaging. International Journal of Mass Spectrometry published new progress about Electric current. 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Application In Synthesis of 110-42-9.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Owen, Rhodri N. published the artcileTowards a universal ion source: Glow Flow mass spectrometry, Synthetic Route of 111-11-5, the main research area is ion source glow flow mass spectrometry.

A helium-microplasma ion source (Glow Flow) has been developed and characterised. It is engineered to be a simple design, of low-cost and can be readily retrofitted to most modern mass spectrometers. Initial assessment of its performance has shown it to be robust, reproducible and of high sensitivity. Glow Flow provides broad non-specific detection of samples from polar through to non-polar chemistries making it of wide utility. A study of persistent organic pollutants, polyaromatic hydrocarbons, low average-mol.-mass polymers (polyethyleneimine, polyethylene glycol, and polypropylene glycol) and a complex mixture of fatty-acid Me esters by direct sample introduction using a nebulised heated nitrogen flow was conducted. The ability to make quant. measurement was investigated using Me stearate and a linear calibration plot gave a R2 = 0.999 and limit-of-detection of �00 fmol. This design is extremely stable, in operation. Typical ions commonly observed are intense protonated mol. ions, radical mol. ions, hydride abstracted ions, and oxygen adduct ions. At present this system is valuable to apply to small mol. anal. (m/z < 1000), and is easily interfaced to gas and liquid chromatog., and likely to be useful for imaging. International Journal of Mass Spectrometry published new progress about Electric current. 111-11-5 belongs to class esters-buliding-blocks, name is Methyl octanoate, and the molecular formula is C9H18O2, Synthetic Route of 111-11-5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics