124-03-8Relevant articles and documents
Switchable oil-water phase separation of ionic liquid-based microemulsions by CO2
Pei, Xiaoyan,Xiong, Dazhen,Pei, Yuanchao,Wang, Huiyong,Wang, Jianji
, p. 4236 - 4244 (2018)
Phase separation of microemulsions plays an important role in many applications such as oil recovery, nanomaterials synthesis, and chemical reactions. However, reversible switching from ionic liquid-based microemulsions to complete oil-water phase separation has not been reported so far. In this work, we developed a novel class of stimuli-responsive microemulsions composed of CO2-responsive ionic liquids, n-pentanol and water. The microstructures and phase behavior of the microemulsion systems before and after the bubbling of CO2 were investigated by electrical conductivity, dynamic light scattering, small-angle X-ray scattering, cryogenic transmission electron microscopy, and optical microscopy. It was found that these microemulsions could be reversibly switched from W/O monophase to complete oil-water phase separation upon alternate bubbling and removal of CO2 at atmospheric pressure. Furthermore, 13C NMR spectroscopy was used to understand the CO2-driven reversible phase separation of the microemulsions. The results suggest that the mechanism behind the reversible phase separation involved the reversible formation of bicarbonate and carbamate from the reaction between CO2 and the anions of the ionic liquids in the presence of water, which resulted in the increase of ionic strength (or vice versa) in the mixture. Using the microemulsions as microreactors, the phase separation protocol was applied in the Knoevenagel reaction for an efficient coupling of a chemical reaction, product separation, and recycling of the microemulsions.
Vernonia oil: Conversion to a mixture of tertiary amines including N,N-Dimethyl-(12S,13R)-Epoxy-cis-9-Octadecenyl amine
Johnson, Nikki S.,Ayorinde, Folahan O.
experimental part, p. 1425 - 1430 (2011/11/11)
Vernonia galamensis is a new potential industrial oilseed crop found in tropical Africa. It is the source of a naturally epoxidized oil called vernonia oil (VO) which is extracted from the seed of the plant. In this study VO was used as the starting material for the synthesis of a mixture of amines, with the major product amine being N,N-dimethyl-(12S,13R)-epoxy-cis-9-octadecenyl amine. VO was transesterified via a base catalyzed methanolysis using sodium methoxide to yield VO methyl esters (VOME). Aminolysis of the VOME with dimethylamine as reagent and solvent under reflux conditions afforded the tertiary amides, with N,N- dimethyl-(12S,13R)-epoxy-cis-9-octadecenyl amide as the major product. The mixture was then subjected to metal hydride reduction with lithium aluminum hydride in diethylether under reflux conditions to obtain the desired amine mixture including N,N-dimethyl-(12S,13R)-epoxy-cis-9-octadecenyl amine. Electron impact mass spectrometry was used to characterize the mixture of amines. Additionally, proton NMR, 13C NMR, and FTIR were used for characterization of N,N-dimethyl-(12S,13R)-epoxy-cis-9-octadecenyl amine. To further confirm the conversion of VO to the amines, the quaternary ammonium salts were synthesized and characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.
Two-Phase Reaction of 1-Bromooctane with Sodium Acetate and Potassium Acetate Catalyzed by Diquaternary Ammonium Salts
Schiefer, H.,Beger, J.,Lorenz, U.
, p. 383 - 398 (2007/10/02)
New unsaturated diquaternary ammonium salts (diquats) were prepared in two ways from ditertiary amines 3 and 1-bromoalkanes or from 1,4-dibromobut-2t-ene and tertiary monoamines.A comparison of their catalytic ability with that of saturated diquats and with that of corresponding monoquats was made.The reaction of n-C8H17Br with NaOAc or KOAc in the two phase system liquid-liquid without an additional solvent is catalyzed more effectively by the unsaturated diquats than by the saturated diquats and the monoquats.Most of the used quats catalyze the ester formation from NaOAc more effectively in the system liquid-liquid, however, the ester formation from KOAc more effectively in the system solid-liquid; KOAc is generally superior to NaOAc in both systems.Consequently, in the phase-transfer catalyzed ester formation from alkali acetate and alkyl halides not only the structure of the quat but also the inorganic cation of the acetate have influence on the rate of conversion.
