scholarly journals Roles of Interfacial Functions in Analytical Chemistry. Extraction spectrophotometric determination of quaternary ammonium salts utilizing ternary ion associate formation with cinchona-alkaloids and tetraiodofluorescein.

1998 ◽  
Vol 47 (12) ◽  
pp. 1013-1020 ◽  
Author(s):  
Tadao SAKAI ◽  
Akihiko HIROSE ◽  
Hideto SASAKI
1997 ◽  
Vol 22 (0) ◽  
pp. 09-14 ◽  
Author(s):  
Zaida FERNÁNDEZ TERRA ◽  
Rubén DEL TÓRO DÉNIZ ◽  
Humberto VARELA DE MOYA

A method has been developed for the extraction and spectrophotometric determination of Hg2+ in a concentration range of 0.2-1.0 mg L-1; following the Lambert-Beer's law using high molecular weight quaternary ammonium salts dissolved in chloroform. The metal complex anion was determined in the extract in the region UV (260 nm).


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Alemayehu Mekonnen ◽  
Alemu Tesfaye

Tandem conjugate addition–alkylation reaction of various amines with α-bromo-α, β-unsaturated ketones resulted in near-quantitative conversions into the corresponding aziridines when the reaction was carried out in the presence of 10 mol% of phase-transfer, PT catalysts in water. Some chiral quaternary ammonium salts derived from Cinchona alkaloids were investigated as water-stable PT catalysts. The scope and limitations of the reaction have also been investigated. The catalytic performances were significantly improved in comparison with the corresponding ordinary quaternary ammonium salt catalysts, and excellent yields (81%–96%) were obtained. Although an increase in the rate of aziridination has been accomplished, no stereoselectivity was observed. The positive values of the protocol have been confirmed.


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