With the specialty of improving the water solubility of chitosan, quaternary ammonium salts have broadened the application of this polysaccharide in food, medicine and pesticides. To identify the effect of quaternary ammonium salts' quantity, single quaternized chitosan N-phenmethyl-N,N-dimethyl chitosan (PDCS), double quaternized chitosan N-(1-pyridylmethyl-2-ylmethyl)-N,N-dimethyl chitosan (M...

Cross-coupling is a fundamental reaction in the synthesis of functional molecules, and has been widely applied, for example, to phenols, anilines, alcohols, amines and their derivatives. Here we report the Ni-catalysed Stille cross-coupling reaction of quaternary ammonium salts via C-N bond cleavage. Aryl/alkyl-trimethylammonium salts [Ar/R-NMe3]+ react smoothly with arylstannanes in 1:1 molar ...

A broad and simple method permitted halide ions in quaternary heteroaromatic and ammonium salts to be exchanged for a variety of anions using an anion exchange resin (A(-) form) in non-aqueous media. The anion loading of the AER (OH(-) form) was examined using two different anion sources, acids or ammonium salts, and changing the polarity of the solvents. The AER (A(-) form) method in organic s...

The properties of aqueous ammonium salt solutions at the air/water surface are presented. By comparison of the properties of ammonium halides solutions with those of sodium halide, we note a close similarity, which indicates that the increments in surface tension may be explained in relation to the hydration enthalpy of anions. We find that the behaviors of the salts with nitrate anions which a...

Asymmetric synthesis of P-chiral phosphorothioic monofluoridic acid ammonium salts was achieved via axis-to-center chirality transfer reactions by using phosphorothioic acid O-esters with a binaphthyl group, and the absolute stereochemistry of the salts was determined by X-ray analyses and by comparison of their CD spectra.

The highly sensitive 5-azidotetrazolate anion was oxidized to its corresponding N-oxide by aqueous oxidation in a buffered oxone solution to the azidotetrazolate 2-oxide anion. After acidic extraction and neutralization with ammonia, the ammonium salt was isolated. Several energetic salts of this novel anion were prepared from the ammonium salt, and in all cases were found to be of lower sensit...

Novel 1,3-dialkylperhydrobenzimidazolinium chloride salts were prepared as precursors of N-heterocyclic carbenes 3a-e by reacting N,N'-dialkylcyclohexandiamine, triethyl orthoformate and ammonium chloride. The salts were characterized spectroscopically and the complexes formed in situ from Pd(OAc)2 and 3 have been tested as catalysts in homogenous Heck and Suzuki reactions.

The pharmacological properties of tertiary sulphonium salts appear to be similar to those of quaternary ammonium salts. The trimethyl+ sulphonium ion, Me3S, resembles the tetramethyl+ ammonioum ion, Me N in its ability to paralyse the frog sartorius preparation (Ing and Wright, 1933): decamethylene bisdimethylsulphonium + + Me2S-(CH2)10-SMe2, resembles decamethonium, + + Me3N-(CH2)0-NMe3, in it...

Shedlovsky's results,16 which differ from all others. There can be no doubt that most if not all, of these minima are spurious. One observation, which we have made may have an important bearing on this problem. In many cases, on addition of the first sample, the resistance of the solution drifted to lower values. The rate of this drift depended on the salt as well. as on the sample. In some ins...

Stable flies are blood feeding parasites and serious pests of livestock. The immature stages develop in decaying materials which frequently have high ammonium content. We added various ammonium salts to our laboratory stable fly rearing medium and measured their effect on size and survival as well as the physical properties of the used media. The addition of ammonium hydroxide, ammonium phospha...