Ionization Constants of Some Organomercuric Hydroxides and Halides

Abstract

The ionization constants of methyl-, ethyl-and phenylmercuric hydroxides and of methylmercuric chloride and bromide have been measured by potentiometric titration. All are weak electrolytes. The solubility products of methyl-and phenylmercuric halides have been found, partly potentiometrically and partly by direct solubility measurements. A convenient way of titrating alkyl mercuric hydroxides is described, and evidence is given to show that a certain method for preparing solid methyl mercuric hydroxide actually leads to the oxide.(1) Most of this work is taken from the Ph.D. thesis of Thomas D.

Complexation of CH3Hg+ with chloride, sulfate and carbonate in NaClO4: construction of thermodynamic models

“…according to literature methods. 13,18 All other reagents were of analytical grade (from Merck and Fluka), with a purity always >99.5%, and were used without further purification. The concentration of the sodium perchlorate employed as ionic medium was tested gravimetrically after evaporation of different aliquots at 110°C.…”

Potentiometric study of the hydrolysis of (CH3)Hg+ in NaClO4: construction of a thermodynamic model

“…14, 499-506 (2000) stoichiometric stability constant values at different ionic strengths and in different ionic media as possible. As stated above, the studies on the hydrolysis of methylmercury found in the literature [8][9][10][11][12][13][14][15][16][17][18][19] have been performed in different ionic media and at unique ionic strengths, so that bibliographic information is not enough to correlate and construct the thermodynamic model. The construction of the thermodynamic model proposed in this work has consequently been performed using only the set of stoichiometric formation constants collected in Table 4.…”

“…37 It has been used in this work to evaluate the activity coefficient. According to MBM, the individual activity coefficient of a charged species can be expressed as Eqn [10], where A = 0.511 dm 3/2 mol À1/2 , I is the ionic strength on the molar scale, Z M the charge on the M ion, Z X that of the ionic species with opposite sign to M and c X its molarity. The B MX term is expressed as Eqn [11], where B MX is the interaction parameter for each ion-pair MX on the molar scale (dm 3 mol À1 ).…”

“…Consequently, it shows a trend to hydrolysis in aqueous solution, as shown in previous work. [8][9][10][11][12][13][14][15][16][17][18][19] However, not all authors propose the same set of hydrolytic species from methylmercury(II) ( Table 1).…”

Methylmercury(II) binding to single-stranded and duplex DNA: complexes formed are distinguishable by optical detection of magnetic resonance spectroscopy.

“…A ca. 50 mM aqueous stock solution ofCH3HgOH was prepared and standardized by published procedures (10). The solution was diluted with the low ionic strength buffer described above to give a CH3HgOH concentration of80 ,tM.…”