A potentiometric study of cationic heteroconjugation equilibria in nitromethane andN,N- dimethylformamide

Capillary zone electrophoresis in non-aqueous solutions: pH of the background electrolyte

“…Dissociation constants of many other acids and bases in organic solvents have been determined by potentiometric titration using a glass electrode calibrated with buffers prepared from picric acid or 2,6-dinitrophenol (see, e.g. [21,22,31,32,[34][35][36][37][38][39][40][41][42][43][44] and references cited therein). Typically, a one-point calibration has been applied and correction for the effect of the ionic strength has been done with the aid of the Debye-Hückel theory.…”

Determination of dissociation constants for coordination compounds of Cr(III) and Co(III) using potentiometric and spectrophotometric methods

“…The minimization of the sum of the squares given in equation (1) is done using Marquardt's method [19]. This method takes into account not only errors in the e.m.f., but also those in titration volume, stock-solution preparation, electrode calibration parameters, and reagent impurities, in addition to the equilibrium constants determined from other measurements [20]. The details of the calculations of equilibrium constants have been described previously [21,22].…”

Basicity comparison for di-substituted 4-nitropyridine derivatives in polar non-aqueous media

“…Of particular interest are their acid-base properties involving acidity (1) of the protonated bases, BH + , and capacity to form stable complex ions, [BHB] + , held together by hydrogen bonds (2). For this reason, (acid + base) equilibria occurring in the systems consisting of heterocyclic N-bases such as pyridine, quinoline, piperidine and their derivatives [8][9][10][11][12], as well as aliphatic and heterocyclic amine N-oxides [13][14][15][16][17][18] have been extensively investigated in our laboratory. Consequently, the values of acidity constants (expressed as pK a ) for variety of heterocyclic organic bases have been determined in non-aqueous solvents such as acetonitrile [14,16], benzonitrile [18], propylene carbonate [10], nitromethane [11], acetone [8,17], cyclohexanone [8], methanol [9], N 0 ,N 0 -dimethylformamide [11,13], dimethyl sulfoxide [12,13], as well as in the mixed solvents [15].…”