Search results for "Ionic"
showing 10 items of 2016 documents
Generalized synthesis of periodic surfactant/inorganic composite materials
1994
THE recent synthesis of silica-based mesoporous materials1,2 by the cooperative assembly of periodic inorganic and surfactant-based structures has attracted great interest because it extends the range of molecular-sieve materials into the very-large-pore regime. If the synthetic approach can be generalized to transition-metal oxide mesostructures, the resulting nanocomposite materials might find applications in electrochromic or solid-electrolyte devices3,4, as high-surface-area redox catalysts5 and as substrates for biochemical separations. We have proposed recently6 that the matching of charge density at the surfactant/inorganic interfaces governs the assembly process; such co-organizatio…
Über die möglichkeit der bildung makrocyclischer polyoxyniethylene. 29. mitt über polyoxymethylene1
1966
Bei der kationischen Polymerisation von 1,3,5-Trioxan in Cyclohexan entstehen Polyoxymethylene, welche partiell thermisch stabil und alkalibestandig sind, ohne das irgendwelche bekamiten stabilen Endgruppen nachgewiesen werden konnten. Moglicberweise handelt es sich hierbei um Makrocyclen. Cationic polymerization of 1,3,5-trioxan in cyclohexane yields polyoxymethylene which is partially stable to heat and to alkali but does not contain any of the known stable endgroups. These polymers possibly have a macrocyclic structure.
ChemInform Abstract: Sustainable Carbon-Carbon Bond Formation Catalyzed by New Oxamate-Containing Palladium(II) Complexes in Ionic Liquids.
2014
New and versatile bis(oxamato)palladate(II) complexes (I) are synthesized and investigated for both Suzuki and Heck coupling reactions in molten tetra-n-butylammonium bromide as ionic liquid.
ChemInform Abstract: A Liquid-Liquid Biphasic Homogeneous Organocatalytic Aldol Protocol Based on the Use of a Silica Gel Bound Multilayered Ionic Li…
2012
Key feature of the title protocol is the use of a cis-ion-tagged proline dissolved in a liquid film on a multilayered ionic liquid covalently bound to silica. The resulting catalytically active material is soaked in cyclohexanone and water to form a semi-transparent gel which then reacts with the aldehyde.
Cyclodehydration of Diols in Acidic Ionic Liquids
2011
Cyclodehydration of Diols in Acidic Ionic Liquids In the presence of sulfonic acid group functionalized Bronsted-acidic ionic liquids, cyclodehydration of 1,2-ethanediol and 1,4-butanediol is investigated. The role of structure and catalytic activity of ionic liquids on the formation of cyclic ethers: 1,4-dioxane and tetrahydrofuran - is determined.
ChemInform Abstract: Modified Photobehavior of Carboxylic Acid Derivatives Induced by Protonation.
1987
Abstract A series of carboxylic acid derivatives 1–6 containing a second interacting function have been converted into the corresponding O -protonated species or acylium ions upon treatment with 96% sulfuric acid or oleum, respectively, at room temperature. The resulting stable cations have been spectroscopically characterized and submitted to irradiation. Cis-trans photoisomerization was observed in the ionic speciesderived from trans -crotonic, fumaric and maleic acids, and maleic anhydride. By contrast protonated crotonolactone 5a+ was found to be photostable. Finally, protonated α-bromobutyrolactone 6a+ was clean and efficiently dehydrohalogenated to 5a+ upon irradiation. Since the norm…
Darstellung und eigenschaften von formazanen aus polyacroleinen. Polymere acroleine, 17. Mitt.1
1960
Die Herstellung von verschiedenen, substituierten Polyacroleinphenylhydrazonen wird beschrieben. Durch Umsetzung mit Diazoniumsalzen entstehen Polymere mit Formazan-Gruppen. Diese lassen sich zu Tetrazolium-Gruppen dehydrieren. Die polymeren Formazane bilden bei geeigneten Substituenten mit Kupfer-und Uranyl-Ionen Komplexe und konnen daher als selektive Ionenaustauscher verwendet werden. Ferner werden einige polymere Azomethine beschrieben. The preparation of various substituted polyacroleinphenylhydrazones is reported. Polymers with formazane groups are obtained by the reaction of diazonium salts, which can be dehydrogenized to tetrazolium-groups. With suitable substitutes, the polymerie f…
Advanced descriptors for long-range noncovalent interactions between SARS-CoV-2 spikes and polymer surfaces.
2021
The recent pandemic triggered numerous societal efforts aimed to control and limit the spread of SARS-CoV-2. One of these aspects is related on how the virion interacts with inanimate surfaces, which might be the source of secondary infection. Although recent works address the adsorption of the spike protein on surfaces, there is no information concerning the long-range interactions between spike and surfaces, experimented by the virion when is dispersed in the droplet before its possible adsorption. Some descriptors, namely the interaction potentials per single protein and global potentials, were calculated in this work. These descriptors, evaluated for the closed and open states of the sp…
Densities and viscosities of imidazolium and pyridinium chloroaluminate ionic liquids
2013
Abstract The chloroaluminate ionic liquids are used in various types of reactions. However, due to their particular vulnerability on water, their physical properties have not been previously investigated very extensively. The densities and viscosities of series imidazolium and pyridinium chloroaluminate ionic liquids having alkyl (butyl, hexyl, octyl) or aralkyl (benzyl, ethylphenyl) chain at the cation, various effective molar fraction of AlCl 3 (χ AlCl3 = 0.5, 0.65, 0.7), as well as they mixture and mixture with common organic solvents (hexane, toluene) were measured at the temperature range 293.15–343.15 K (20–70 °C). Densities, and particularly viscosities decrease with the increase of…
Complexes of star-shaped cationic polyelectrolytes with anionic liposomes: Towards multi-liposomal assemblies with controllable stability
2016
Abstract Complexes were formed via the electrostatic interaction between 30–50 nm anionic liposomes and a star-shaped polyelectrolyte, poly{[2-(methacryloyloxy)ethyl]trimethyl ammonium iodide}, having cationic arms that radiate from a silicon-based central core. The complexation was investigated with attention given to assessing the capacity of the cationic stars for the anionic liposomes (both liquid and solid); the integrity of the complexed liposomes; and the stability of the resulting star/liposome complexes in aqueous salt solutions. We have found that by changing the content of anionic groups in the liposomal membrane as well as the phase-state of membrane, the stability of star/lipos…