The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene ph...

We studied the effects of quaternary bis-phosphonium and bis-ammonium salts of pyridoxine with lipophilic substituents on the survival and morphology of Staphylococcus aureus cells. We found that, while originating from the same base, they exhibit considerably different antimicrobial mechanisms. In the presence of Ca(2+) ions the MIC and MBC values of ammonium salt increased 100-fold, suggestin...

Some phosphorus chemical shifts of quaternary phosphorium salts had previously been reported4 and it was shown that these chemical shifts could be linearly related to the sum of the ob values5 for the corresponding groups in tertiary phosphines. The op values are group contributions which have been scaled so that the methyl group has a value of zero, in analogy to H a m m e t and T a f t o-para...

The interaction of pyridine-4(-3,-2)aldoxime has been studied whit 3-bromo-N,N,N-trialkyl-2oxo(-hydroxyimino)-1-propanaminium bromide. The structure of all synthesized compounds was determined by elemental analysis as well as by physical and chemical methods. All synthesized compounds were tested for reactivation of phosphorylated acetylcholinesterase. Using fragments of the molecules (an oxime...

A molecular library of quaternary ammonium salts (QASs), mainly composed of symmetrical bis-quaternary heterocyclic bromides exhibiting choline kinase (ChoK) inhibitory activity, were evaluated for their ability to inhibit acetyl- and butyrylcholinesterase (AChE and BChE, respectively). The molecular framework of QASs consisted of two positively charged heteroaromatic (pyridinium or quinolinium...

We herein report our efforts to obtain a new class of systematically modified bifunctional (thio)urea-containing quaternary ammonium salts based on easily obtainable chiral backbones. Among the different classes of catalysts that were successfully synthesized, those based on trans-1,2-cyclohexane diamine were found to be the most powerful for the asymmetric α-fluorination of β-keto esters. Sele...

Readily available chiral ammonium salts derived from cinchona alkaloids have proven to be effective phase transfer catalysts in the asymmetric Michael reaction of 3-substituted isoindolinones. This protocol provides a convenient method for the construction of valuable asymmetric 3,3-disubstituted isoindolinones in high yields and  moderate to good enantioselectivity. Diastereoselectivity was al...

Sodium bentonite was subjected to the effect of two new homologue series of chlorides (alcoxymethyl) dimethyloctyloamonium chlorides and 3-alcoxymethyl-1-octylimidazole chlorides with the hydrophobic substituents of the same length. Morphology of the obtained modified bentonite was studied under scanning electron microscope [SEM] and the degree of adsorption of the ammonium salts was determined...

The use of laser microprobe mass spectrometry (LMMS) for the structural characterization of thermolabile quaternary phosphonium salts has been evaluated. A comparison has been made between LM mass spectra obtained by direct analysis of "neat" organic salts and the corresponding "matrix-assisted" LM mass spectra. Main limitations of LMMS for the direct analysis of neat organic salts (i.e., no ma...

Imidazolium, pyridinium, pyrrolidinium, piperidinium, morpholinium, and quaternary ammonium bis(trifluoromethylsulfonyl)imide salts were functionalized with a carboxyl group. These ionic liquids are useful for the selective dissolution of metal oxides and hydroxides. Although these hydrophobic ionic liquids are immiscible with water at room temperature, several of them form a single phase with ...