Search results for "ethanol"
showing 10 items of 2041 documents
Effect of structural parameters on the polarizabilities of methanol clusters: a hirshfeld study
2008
The polarizabilities of fifty methanol clusters (CH3OH)n, n = 1 to 12, were calculated at the B3LYP/6-311++G** level of theory and partitioned into molecular contributions using the Hirshfeld-I method. The resulting molecular polarizabilities were found to be determined by the polarizabilities of the two parts of the molecule, the hydrophilic hydroxyl group and the hydrophobic methyl group, each exhibiting a different dependency upon the local environment. The polarizability of the hydroxyl group was found to be dependent on the number, type, and strength of the hydrogen bonds a methanol molecule makes, whereas the polarizability of the methyl groups is mostly influenced by sterical hindran…
Linear free energyortho-correlations in the thiophene series. Part IX . Kinetics of esterification with diazodiphenylmethane of some 3-, 4-, and 5-su…
1981
The rate constants for the esterification of some 3-, 4-, and 5-substituted thiophene-2-carboxylic acids with diazodiphenylmethane in methanol at 25° have been measured. The reactivity of some para- and ortho-substituted benzoic acids has also been determined. Logarithmic kinetic constants for ortho-, meta-, and para-like substituted thiophene-2-carboxylic acids furnish an excellent linear free energy relationship when plotted versus Δpka (β 0.89, r 0.989, C.L. > 99.9%, n 18, i 0.04), thus confirming the peculiar behaviour of five-membered ring derivatives. The correlation with σH values offers an additional proof of the hyper-ortho character of the 2,3-relation in thiophene derivatives. pa…
A Covalently Cross-linked Polyetheretherketone Proton Exchange Membrane for DMFC
2009
The proton exchange membrane was prepared by covalent cross-linking sulfonated-sulfinated polyetheretherketone. The cross-linked membrane showed high proton conductivity (0.04 S/cm) with suitable water uptake, low methanol permeability (2.21 × 10-7 cm2/s) and good electrochemical stability. The results suggested that cross-linked polyetheretherketone membrane is particularly promising to be used as proton exchange membrane for the direct methanol fuel cell application.
Biosensors Applied to Quantification of Ethanol in Beverages
2019
Abstract The quality control in the processing of alcoholic beverages is major concern for producers and regulatory agencies, particularly for ethanol content which is mandatory in the label of alcoholic beverages in many countries. The use of biosensors can be of great interest in this context that usually requires laborious and costly protocols. Biosensors are composed by two principal components: the biological recognition element and the transducer. Particularly for ethanol evaluation, the use of alcohol dehydrogenase (ADH) or oxidase (AOX) is commonly reported in the literature which allowed the production of optical and electrochemical biosensors. These biosensors can aid in the deter…
Corrigendum to “Phase equilibria for the ternary systems ethanol, water + ethylene glycol or + glycerol at 101.3 kPa” [Fluid Phase Equilib. 341 (2013…
2013
Alkylumlagerungen und acidolyse der ethylidenbrücken bei der synthese von ethylidendiphenolen
1990
For the synthesis of symmetrical and unsymmetrical ethylidenediphenols the corresponding hydroxyphenylethanols (1a–c) were prepared by hydrogenation of hydroxyphenyl methyl ketones with hydrogen/Raney nickle or with lithium aluminium hydride. Condensations of the hydroxyphenylethanols with different phenols under the usual acidic conditions gave products formally resulting form transalkylations. Only the reaction of 1-(3-bromo-2-hydroxy-5-methylphenyl)ethanol (1c) with p-cresol gave the expected product 2d with 82% yield. Experiments with ethylidenediphenols showed that with acids in presence or absence of phenols cleavage and recondensations take place leading to products of formal transal…
ChemInform Abstract: ortho Effect on the Nitrosation of the 2,3-Diphenyl-5-(2-methoxyphenyl)pyrrole.
1990
A comparison of the behaviour on the nitrosation of the isomers 5-(2-methoxyphenyl)- (1a) 5-(3-methoxyphenyl)- (1b) and 5-(4-methoxyphenyl)2,3-diphenylpyrroles (1c) carried out in the usual way with iso-amyl nitrite in a solution of sodium ethoxide in ethanol evidences that 1a is dramatically less reactive with respect to 1b and 1c. The different reactivity was ascribed to the occurrence of a strong hydrogen bond involving pyrrole NH and the ortho-methoxy group.
orthoeffect on the nitrosation of the 2,3-diphenyl-5(2-methoxyphenyl)pyrrole
1990
A comparison of the behaviour on the nitrosation of the isomers 5-(2-methoxyphenyl)- (1a) 5-(3-methoxyphenyl)- (1b) and 5-(4-methoxyphenyl)2,3-diphenylpyrroles (1c) carried out in the usual way with iso-amyl nitrite in a solution of sodium ethoxide in ethanol evidences that 1a is dramatically less reactive with respect to 1b and 1c. The different reactivity was ascribed to the occurrence of a strong hydrogen bond involving pyrrole NH and the ortho-methoxy group.
SY26-4REVIEWING THE NEUROBIOLOGICAL EFFECTS OF SALSOLINOL: ROLE OF THE MU OPIOID RECEPTORS
2015
During the last decades Salsolinol (SAL), a condensation product from dopamine (DA) and acetaldehyde that appears in the brain of humans and rodents as a consequence of brain metabolism of ethanol, has been proposed as a key component in the development of alcohol use disorders. Although evidence has been published …