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INDUSTRIAL ORGANIC SOLVENTS
Published in Nicholas P. Cheremisinoff, Industrial Solvents Handbook, Revised And Expanded, 2003
The chief functional group for the ether family is the O-R group called the alkoxy group. The general structure for ethers is R-O-R*. Symmetrical ethers are those where the alkyl groups, R and R', are the same. Asymmetrical ethers are those where the R and R' are different. Simple ethers can be named by naming the alkyl groups alphabetically followed by the word "ether". For example, CHrO-CHrCH1 would be called using this common name approach as ethyl methyl ether. However for more complex ethers that have branching, using this common name approach is considerably more difficult. The IUPAC has come up with some rules that allow the naming of complex ethers. The rules are similar to those used in naming alcohols except the O-R group is named as any other branched group. Using the rules for alkanes, alkenes, or alkynes with the alkoxy groups identified on the longest continuous chain. The rules are as follows:
Characterization of emission-performance paradigm of a DI-CI engine using artificial intelligent based multi objective response surface methodology model fueled with diesel-biodiesel blends
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Kiran Kumar Billa, G. R. K. Sastry, Madhujit Deb
The base oil is extracted from the Jatropha seeds through mechanical expellers. The seeds were dried enough to drain out the humidity before fed to the expellers. The oil thus obtained is filtered and transesterification is done. Transesterification is a chemical process of swapping an alkoxy group from an ester compound with another alcohol catalyzed by adding a base and an acid. Bases catalyze the reaction by replacing a proton from methyl alcohol, thus allowing to more reactive. Acids catalyze the reaction with donating a proton to the carbonyl group of the veggie oil, thus allowing it more reactive (Misra and Murthy 2011). The filtered Jatropha crude oil obtained is mixed with methyl alcohol in the ratio 1:10 and the mixture is heated up to four to five hours at a temperature of 60°C in the presence of sulfuric acid and base catalyst KOH. The content is allowed to cool, and Jatropha methyl ester is separated from the glycerin, washed with saline water (2%) to remove traces and to neutralize the sulfuric acid. The content is boiled to remove moisture/water left in the methyl ester. The simple transesterification reaction (Fadhil, Al-Tikrity, and Albadree 2015) is given below.
The solvatochromism, electronic structure, electric dipole moments and DFT calculations of benzoic acid liquid crystals
Published in Liquid Crystals, 2020
We have been seen strong broad bands with a maximum in the 252–280 nm regions of electronic absorption spectra of 4DDOBA in various solvents. These electronic transitions is derived from alkoxy-phenyl-carboxylic interactions and, thus, these transitions are π-π* transitions. The first band is recorded in the range of 291–328 nm while the second one is observed in the range of 575–619 nm. The short wavelength fluorescence is emitted from LE state while long wavelength band comes from the ICT. As can be seen from Figure 5, dimer structure C = O … H-O cyclic hydrogen bonds of aromatic acids is done. In this figure, ICT done between donor and acceptor groups have quenched due to the decrease of the electron density of alkoxy group oxygen. As seen from Table 1, electronic absorption of 4DOBA and 4DDOBA molecules occurred hypsochromic effect, whereas electronic absorption of 4UDOBA molecule was a bathochromic effect. In other words, as the solvent polarity increased, the electronic transition energy of 4DOBA and 4DDOBA decreased, whereas the electronic transition energy in of 4UDOBA increased. When we look at the fluorescence wavelengths, 4DOBA and 4DDOBA have bathochromic effect, while 4UDOPA has a hypsochromic effect.
Chemistry of hydroperoxycarbonyls in secondary organic aerosol
Published in Aerosol Science and Technology, 2018
Demetrios Pagonis, Paul J. Ziemann
It is important to note here that because of differences in gas-phase reaction mechanisms, hydroperoxycarbonyls formed in the atmosphere would most likely contain an alkyl group instead of the alkoxy group that is present in the model α-alkoxy hydroperoxyaldehyde, cyclic peroxyhemiacetal, and their decomposition products. Despite this difference, the consistency of our results with prior studies of rates (Mertes et al. 2012; Krapf et al. 2016) and products of decomposition of peroxyhemiacetals (Durham, Wurster, and Mosher 1958) leads us to believe that the decomposition pathways of a hydroperoxycarbonyl with an alkoxy substituent are similar to those of a hydroperoxycarbonyl with an alkyl substituent. The alkoxy hydroperoxyacid, alkoxy hydroxycarbonyl, alkoxy cyclic hemiacetal, acid ester, aldoacid, and aldoester decomposition products (Figure 3) would then become a hydroperoxyacid, hydroxycarbonyl, cyclic hemiacetal, ketoacid, and dicarbonyl (Figure S3). And for the peroxyacetal and its decomposition products, one of the alkoxy groups would be replaced by an alkyl group so that the diester, acetal ester, and diacetal would then become a ketoester, ketoacetal, hydroxyester, and hydroxyacetal (Figure S3). Furthermore, in the atmosphere, the alkoxy groups in all these compounds would have been added by reactions with the large variety of low volatility multifunctional compounds containing hydroxyl groups (instead of 1-propanol) that are present in SOA, leading to the formation of much larger oligomeric compounds. These compounds would in turn be amenable to acid-catalyzed exchange reactions with other alcohols or water.