نتایج جستجو برای: ammonium salts
تعداد نتایج: 51521 فیلتر نتایج به سال:
The microwave synthesis of several quaternary ammonium salts is described. The synthesis provides comparable or better yields than published methods with reduced reaction times and in the absence of solvent.
A series of porous polymers bearing functional quaternary ammonium salts were solvothermally synthesized through the free radical copolymerization of divinylbenzene (DVB) and functionalized quaternary ammonium salts. The obtained polymers feature highly cross-linked matrices, large surface areas, and abundant halogen anions. These polymers were evaluated as heterogeneous catalysts for the synth...
-Existing methods of measuring atmospheric aerosol strong acidity adequately prevent neutralization of fine-particle acidity by removing coarse alkaline particles and gaseous ammonia from air samples. However, these techniques do not consider particle interactions on the collection medium; therefore, they may still underestimate the actual aerosol acidity. Assessment of acid neutralization due ...
A series of gemini quaternary ammonium salts (chlorides and bromides), with various hydrocarbon chain and spacer lengths, were tested. These compounds exhibited antibacterial activity against both Gram-positive and Gram-negative bacteria and were not mutagenic. The strongest antibacterial effect was observed for TMPG-10 Cl (against Pseudomonas aeruginosa ATCC 27853) and TMPG-12 Br (against Stap...
Various levels of protection against x-irradiation damage in bacteriophage T1 may be obtained by the addition of inorganic salts to the aqueous virus suspensions during irradiation. The highest survival values are obtained with the nitrite salts, and their protective power is attributed primarily to their function as reducing agents. The nitrate ion shows greater protection than the correspondi...
Quaternary ammonium compounds are an important class of molecules with wide variety of applications, mainly in the antimicrobial field. Quaternary ammonium compounds have the ability to bind with the anionic moiety of phospholipids of the bacterial membrane, disrupting the cell membrane of the microorganisms. However, classical quaternary ammonium salts can have adverse effects on the environme...
Although the hydrogen-bonding ability of the α hydrogen atoms on tetraalkylammonium salts is often discussed with respect to phase-transfer catalysts, catalysis that utilizes the hydrogen-bond-donor properties of tetraalkylammonium salts remains unknown. Herein, we demonstrate hydrogen-bonding catalysis with newly designed tetraalkylammonium salt catalysts in Mannich-type reactions. The structu...
Magnesium phosphate cements (MPC) are the most developed kind of chemically bonded ceramics which form through the reaction of magnesium oxide and soluble phosphate salts. Therefore, study of different magnesium phosphate cement systems is considered important according to the type of phosphate agent used. In this study, effect of mono-ammonium phosphate (MAP), di-ammonium phosphate (DAP), and ...
Two novel calix[6]cryptamides bearing a tren-based cap have been synthesized and their host-guest properties have been investigated by (1)H and (19)F NMR spectroscopy. One of them behaves as a remarkable heteroditopic receptor toward either polar neutral guests, anions or contact ion pairs. It has been shown that only F(-) can be encapsulated into the tris-amido cap of this host. Moreover, the ...
In view the of wide scope of structural information of biomolecules in biocompatible ionic liquids (ILs) in various applications including chemical and biochemical, it is essential to study the productive preferential interactions between biological macromolecules and biocompatible ILs. We have therefore explored the stability and activity of α-chymotrypsin (CT) in the presence of five ILs from...
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