scholarly journals Synthesis of a novel arginine-modified starch resin and its adsorption of dye wastewater

RSC Advances ◽  
2020 ◽  
Vol 10 (67) ◽  
pp. 41251-41263
Author(s):  
Hao Zhang ◽  
Panlei Wang ◽  
Yi Zhang ◽  
Bowen Cheng ◽  
Ruoying Zhu ◽  
...  
Keyword(s):  
Aldol Condensation ◽  
Condensation Reaction ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Modified Starch ◽  
Dye Wastewater ◽  
Aldehyde Groups ◽  
Starch Molecule

In the side reaction, the two aldehyde groups in the glutaraldehyde molecules should undergo an aldol condensation reaction with the hydroxyl group in the starch molecule, which has been corrected.

scholarly journals Nonanal Sensor Fabrication Using Aldol Condensation Reaction Inside Alkali-Resistant Porous Glass

2021 ◽  
pp. 1-1
Author(s):  
Masato Tsujiguchi ◽  
Takashi Aitoku ◽  
Hironori Takase ◽  
Yasuko Yamada Maru
Keyword(s):  
Porous Glass ◽  
Aldol Condensation ◽  
Condensation Reaction ◽  
Sensor Fabrication

Liquid-phase aldol condensation of cyclohexanone on aluminium and iron oxides

1982 ◽  
Vol 47 (8) ◽  
pp. 2235-2245 ◽  
Author(s):  
Zdeněk Vít ◽  
Lubomír Nondek ◽  
Jaroslav Málek
Keyword(s):  
Iron Oxides ◽  
Aldol Condensation ◽  
Condensation Reaction ◽  
Complex Function ◽  
Acid Sites ◽  
Basic Site ◽  
Catalyst Poisoning ◽  
Iron Hydroxides ◽  
Transient Complex ◽  
Kinetics Of

The kinetics of the aldol condensation of cyclohexanone in decalin were investigated at 210 °C on catalysts prepared by drying and calcining the aluminium and iron hydroxides at 110-850 °C. The effect of catalyst poisoning by benzoic acid and pyridine on the course of the condensation reaction and aldol retroaldolisation was also examined. The kinetics of the cyclohexanone condensation can be described by means of Langmuir-Hinshelwood equations which are in agreement with a mechanism involving adsorption of cyclohexanone on a basic site to form a transient complex, reaction of this complex with a cyclohexanone molecule affording the aldol, the rate determining interaction of the aldol with free basic and acid sites yielding 2-(1-cyclohexen-1-yl)cyclohexanone and water and desorption of these products from the catalyst surface. The proposed kinetic model is supported by the results of catalyst poisoning. The activity of aluminium and iron oxides in the condensation of cyclohexanone is a complex function of their basicity and acidity depending strongly on the calcination temperature.

Structure of a new oligomer of glutaraldehyde produced by aldol condensation reaction

1991 ◽  
Vol 56 (2) ◽  
pp. 694-697 ◽  
Author(s):  
Toshio Tashima ◽  
Masahiro Imai ◽  
Yoshihiro Kuroda ◽  
Shigemasa Yagi ◽  
Terumichi Nakagawa
Keyword(s):  
Aldol Condensation ◽  
Condensation Reaction

scholarly journals Synthesis and biotical activity of bacterial cellulose 6-(2-phthalimidoethanesulfonate)

2020 ◽  
Vol 61 (2) ◽  
pp. 29-36
Author(s):  
Zoya P. Belousova ◽  
Keyword(s):  
Bacterial Cellulose ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Cellulose Derivatives ◽  
Wound Surface ◽  
Reaction Products ◽  
Absorption Bands ◽  
Hydroxymethyl Group ◽  
Antibacterial And Antifungal

Bacterial cellulose obtained by culturing Gluconacetobacter sucrofermentans in HS environment was converted to sulfonate derivatives using methane-, toluene- and 2-phthalimidoethanesulfonic acids in pyridine. When the ratio of the starting reagents is 1 : 1, the modification of bacterial cellulose according to the primary hydroxyl group of glucopyranose fragments is most likely. The formation of 6-substituted bacterial cellulose derivatives was observed in the reaction mixture. The IR spectra of the reaction products contain absorption bands, which are specific for (O–SO2) group in the region 1377-1338 cm−1 (as), 1178-1154 cm−1 (s), fragments of the corresponding sulfonic acids, as well as free hydroxyl groups of glucopyranose in the region 3495-3382 cm−1. Bacterial cellulose 2-phthalimidoethanesulfonate was dissolved in pyridine. After drying with a desiccant in a desiccator, it turned into a dense transparent film of brown color. The increased molecular film allows to explain the side reaction occurring between the oxo group and fragments of one of the chains of modified cellulose and the non-substituted hydroxymethyl group. The IR spectrum of bacterial cellulose 6-(2-phthalimidoethanesulfonate) contains absorption bands in the region 1711 cm−1, which are specific for (Ar–CO–O) group, and absorption bands in the region 1618 cm−1, which prove the presence of (CO–NH) group. In order to impart antibiotic properties to the bacterial cellulose 6-(2-phthalimido-ethanesulfonate) film, it was physically modified with clotrimazole. The obtained experimental data showed that the films subjected to treatment with a 1% solution of clotrimazole have antibacterial and antifungal effects and prevent the growth of pathogenic microbiota on the wound surface. The exit rates of clotrimazole from the bacterial cellulose 6-(2-phthalimidoethanesulfonate) film and from the pure bacterial cellulose film differed, but only slightly. 2-Phthalimidoethanesulfonate bacterial cellulose films can be used to form composites of effective wound covering, since in addition to the unique properties of bacterial cellulose itself (low allergenicity and adhesion to the wound surface, high hygroscopicity) they will have a regenerating effect.

scholarly journals Understanding the Lack of Reactivity of 2,4-Dihydroxybenzaldehyde Towards the Biginelli Adduct Using Density Functional Theory Molecular Modeling

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 521
Author(s):  
Virginia Flores-Morales ◽  
Eduardo D. Ayala-Medrano ◽  
José García-Elías ◽  
Margarita L. Martínez-Fierro ◽  
Edgar Marquez ◽  
...  
Keyword(s):  
Density Functional ◽  
Natural Bond Orbital ◽  
Activation Enthalpy ◽  
Computational Study ◽  
Theoretical Calculations ◽  
Condensation Reaction ◽  
Biginelli Reaction ◽  
Hydroxyl Group ◽  
Functional Theory ◽  
Multiple Substitution

The Biginelli reaction is a multicomponent reaction for obtaining dihydropyrimidinthiones quickly, with multiple substitution patterns. The reaction mechanism remains unclear. Three possible pathways proposed for the reaction are the iminium route, an enamine intermediate, and the Knoevenagel pathway. However, when thiourea was used, no theoretical calculations were reported. Thus, based on the literature, the iminium pathway was used to obtain evidence explaining the lack of reactivity of 2,4-dihydroxybenzaldehyde towards the Biginelli adduct, compared with 4-hydroxybenzaldehyde. This computational study, carried out using the B3LYP/6-31++G(d,p) level of theory, showed an increment of 150 kJ/mol in the activation energy of the slowest pathway, due to the presence of a hydroxyl group in position 2 (ortho) of the aromatic aldehyde, decreasing its reactivity. Natural bond orbital (NBO) calculations suggest that the determinant steps are simultaneous, i.e., the polarization of the carbonyl group and its corresponding protonation by the hydrogen of the SH fragment of the thiourea tautomer. The activation enthalpy values suggest that the nucleophile attack takes place later on the compound 2,4-dihydroxybenzaldehyde compared to 4-hydroxybenzaldehyde-TS, confirming that the OH group in position 2 hinders the condensation reaction.

Newly Synthesized Branch-type Aromatic Oxadiazole Polymer and Binary Fluorescence Patterning on its Film

2007 ◽  
Vol 19 (5-6) ◽  
pp. 531-540 ◽  
Author(s):  
Moon Soo Choi ◽  
Hyung Jun Kim ◽  
Taek Seung Lee ◽  
Won Seok Lyoo
Keyword(s):  
Coupling Reaction ◽  
Side Reaction ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Aromatic Side Chain ◽  
Suzuki Coupling Reaction ◽  
Color Changes ◽  
Fluorescence Color ◽  
Before And After ◽  
Photochemical Cleavage

Aromatic side-chain oxadiazole polymer linked with 9,9'-dioctylfluorene was successfully synthesized via Suzuki coupling reaction. Hydroxyphenyl group was attached in the 2-position of the oxadiazole unit in the polymer side chain to control the optical properties of the polymer. We confirmed the presence of the t-butoxycarbonyl group on the hydroxyl group using thermogravimetric analysis, which was incorporated to avoid side reaction during polymerization. We also performed the simple and easy fabrication method for the dual fluorescence image using photochemical cleavage of the t-butoxycarbonyl group from the polymer to induce fluorescence color changes before and after UV irradiation.

scholarly journals Hf-based metal–organic frameworks as acid–base catalysts for the transformation of biomass-derived furanic compounds into chemicals

2018 ◽  
Vol 20 (13) ◽  
pp. 3081-3091 ◽  
Author(s):  
Sergio Rojas-Buzo ◽  
Pilar García-García ◽  
Avelino Corma
Keyword(s):  
Aldol Condensation ◽  
Condensation Reaction ◽  
Metal Organic Frameworks ◽  
Acid Base ◽  
Base Catalysts ◽  
Metal Organic ◽  
Furanic Compounds

Hafnium-based metal–organic frameworks are promising catalysts for upgrading biomass derivatives via an aldol condensation reaction.

ChemInform Abstract: Direct Aldol Condensation Reaction of Ethyl Diazoacetate with Trifluoromethyl Ketones.

ChemInform ◽  
2012 ◽  
Vol 43 (10) ◽  
pp. no-no
Author(s):  
Han-Feng Cui ◽  
Lian Wang ◽  
Li-Jun Yang ◽  
Jing Nie ◽  
Yan Zheng ◽  
...  
Keyword(s):  
Aldol Condensation ◽  
Condensation Reaction ◽  
Ethyl Diazoacetate ◽  
Trifluoromethyl Ketones
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