A potentiometric study of acid–base equilibria of trimethylamineN-oxide systems in non-aqueous media

1998 ◽  
Vol 30 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Lech Chmurzyński ◽  
Zenon Pawlak
Keyword(s):  
Aqueous Media ◽  
Acid Base ◽  
Oxide Systems ◽  
Potentiometric Study

A potentiometric study of (acid+base) equilibria in substituted 4-nitropyridine N-oxide systems in methanol and dimethyl sulfoxide

2007 ◽  
Vol 39 (2) ◽  
pp. 309-315 ◽  
Author(s):  
Łukasz Gurzyński ◽  
Aniela Puszko ◽  
Mariusz Makowski ◽  
Lech Chmurzyński
Keyword(s):  
Dimethyl Sulfoxide ◽  
Acid Base ◽  
Oxide Systems ◽  
Potentiometric Study

Potentiometric study of the acid-base equilibrium of loprazolam at 25 �C in 0.1M NaCl medium

1996 ◽  
Vol 122 (1-2) ◽  
pp. 133-141 ◽  
Author(s):  
Benito Fern�ndez ◽  
Ma Jesus Arenaza ◽  
Luis Angel Fern�ndez ◽  
Ma Angeles Olazabal
Keyword(s):  
Acid Base ◽  
Potentiometric Study ◽  
Base Equilibrium ◽  
Acid Base Equilibrium

scholarly journals Formation of highly quaternized N,N,N-trimethylchitosan: a chemoselective methodology in aqueous media

2019 ◽  
Vol 91 (3) ◽  
pp. 489-496 ◽  
Author(s):  
Youssouf D. Soubaneh ◽  
Steeven Ouellet ◽  
Caroline Dion ◽  
Jonathan Gagnon
Keyword(s):  
Biomedical Applications ◽  
Chemical Shifts ◽  
Aqueous Media ◽  
Acid Base ◽  
Specific Chemical ◽  
H Nmr ◽  
Low Degree ◽  
Simple Step ◽  
Carbonate Salt

Abstract N,N,N-Trimethylchitosan (TMC) represents a rare example of cationic polysaccharides and numerous studies have shown its potential in biological and biomedical applications. TMC with high degrees of quaternization (DQ) were synthesized from N-methylation of N,N-dimethylchitosan (DMC), which was obtained by reductive alkylation of high molecular weight chitosan in a simple step process and in good yields. The effects of base and solvents were evaluated on the quaternization reaction. The N-methylation of DMC was performed selectively by CH3I and carbonate in water where quaternization was achieved quantitatively with a low degree of O-methylation (17 %). Moreover, the greener procedure allows easy recovery and purification by conventional filtration as a carbonate salt, in which the anion can be exchanged by an acid-base reaction. Quantification of DQ involving 1H NMR integration of methyl peaks must be performed on protonated TMC. High field NMR spectra of TMC showed two specific chemical shifts for anomeric peaks (5.0 and 5.4 ppm) that can also be used for the determination of DQ. This latter method avoids the superimposition problems with other pyranosyl peaks.

A potentiometric study of acid–base properties of the (phenol+phenolate) systems in acetonitrile and, (acetonitrile+cyclohexane) solvent system

2003 ◽  
Vol 35 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Anna Kozak ◽  
Małgorzata Czaja ◽  
Mariusz Makowski ◽  
Dagmara Jacewicz ◽  
Aleksandra Da̧browska ◽  
...  
Keyword(s):  
Solvent System ◽  
Acid Base ◽  
Potentiometric Study ◽  
Base Properties

N-confused porphyrin possessing glucamine-appendants: Aggregation and acid/base properties in aqueous media

2008 ◽  
Vol 18 (24) ◽  
pp. 6394-6397 ◽  
Author(s):  
Yoshiya Ikawa ◽  
Hiroaki Ogawa ◽  
Hiroyuki Harada ◽  
Hiroyuki Furuta
Keyword(s):  
Aqueous Media ◽  
Acid Base ◽  
Base Properties
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