A novel method with quaternary ammonium salts as internal additives has been applied to the mass scale calibration of time-of-flight secondary ion mass spectrometry (TOF-SIMS). Five kinds of quaternary ammonium salts, octyltrimethylammonium bromide (C8TMA), tetradecyltrimethylammonium chloride (C14TMA), octadecytrimethylammonium chloride (C18TMA), cetylpyridinium chloride (CPC) and benzyldimeth...

Quaternary ammonium and phosphonium salts have been screened for their toxic effect on HeLa and K562 cancer cell lines, as well as on normal HUVEC cells. Tri-n-butyl-n-hexadecylphosphonium bromide, the first phosphonium salt with a halogen anion tested against HeLa cells, was 12 times more potent (IC50 <5 μm after 24 and 48 h) than the clinically used reference compound cisplatin and 17 times m...

The microwave synthesis of twenty quaternary ammonium salts is described. The syntheses feature comparable yields to conventional synthetic methods reported in the current literature with reduced reaction times and the absence of solvent or minimal solvent.

Convenient and inexpensive ammonium salts such as NH(4)Cl and aqueous NH(3) solution are found to be readily utilized in the Cu-catalyzed room temperature N-arylation of aryl halides, providing N-unprotected aniline derivatives in high yields.

• The discovery of the first crown ether is described. Forty-seven other aromatic and saturated polyethers were synthesized and their properties determined. Many form stable crystalline complexes with alkali and alkaline earth salts. Some saturated crown ethers solubilize potassium hydroxide and permanganate in aromatic hydrocarbons, EThe SC!5 indicates that this paper has been cited in over 1,...

The cyclocondensation reaction between rigid, electron-rich aromatic diamines and 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium (Zincke) salts has been harnessed to produce a series of conjugated oligomers containing up to twelve aromatic/heterocyclic residues. These oligomers exhibit discrete, multiple redox processes accompanied by dramatic changes in electronic absorption spectra.

When studying some organic ammonium salts as potential solubilizers [1—4] we found that they possessed good surface-active properties as well as significant antimicrobial activity. The assumption of favourable relationship between the effect of the ammonium group and the properties of the alkanecarboxylic acid and of its esters, respectively, prompted us to prepare the title compounds and study...

The reaction of cinchonidine (cinchonine)-derived ammonium salts with nitroolefins in the presence of Cs2CO3 to afford optically active isoxazoline N-oxides with excellent ee and high de values has been developed.

A novel class of tartaric acid-derived N-spiro quaternary ammonium salts was synthesised starting from known TADDOLs. These compounds were found to catalyse the asymmetric α-alkylation of glycine Schiff bases with high enantioselectivities and in good yields.

Calix[4]arene derivatives supported on monolayer protected gold clusters show a remarkable enhanced binding efficiency towards quaternary ammonium salts in homogeneous solution of apolar solvents with respect to the corresponding unsupported hosts.