Interaction of Alkyltin(IV) Compounds with Ligands of Interest in the Speciation of Natural fluids: Complexes of (CH3)2Sn2+ with Carboxylates

Abstract

Complex formation by (CH3)2Sn2+ with acetate (ac), malonate (mal), 1,2,3‐propane‐tricarboxylate (tricarballylate, tca) and 1,2,3,4‐butanetetracarboxylate (btc) ligands in aqueous solution is reported. The study has been performed by potentiometry ([H+]–glass electrode) at T=25 °C, and in the 0⩽I⩽1 mol dm−3 ionic strength range. In order to evaluate the salt effects on the formation constants of the complex species, and to contribute to the definition of the chemical speciation of diorganotin(IV) compounds in natural waters where carboxylic ligands are naturally present, interactions of NaCl (which is the major component of all natural fluids), with the components of the systems under investigation have also been considered. A model for the ionic strength dependence of the formation constant was used in order to calculate the values of thermodynamic constants, at infinite dilution, for all the proposed species, by considering hydrolytic species too. A relationship between the charges on the different ligands considered and the stabilities of the complex species formed is also discussed. © 1997 John Wiley & Sons, Ltd.

Inorganic speciation of organotin(IV) cations in natural waters with particular reference to seawater

“…In this work we used the formation constants of carbonate and fluoride species at different ionic strengths (NaCl ionic medium) and T = 25°C. Details of other experimental investigations and procedures used to determine hydrolysis constants and chloride, sulphate and carboxylate complex formation constants have been published in previous papers (Cannizzaro et al, 1998;De Stefano et al, 1996, 1997a, 1999b, 1999c, 1999d. Table 1 summarises the experimental conditions used for all the systems investigated in different ionic media and ionic strength ranges.…”

“…On the basis of the pioneering work of Tobias andco-workers (McGrady andTobias, 1964, 1965;Tobias 1966;Tobias and Friedline 1965;Tobias and Yasuda 1964;Tobias et al, 1962Tobias et al, , 1966, demonstrating the strong tendency to hydrolysis of the organotin cations, according to the equation (1) systematic studies were performed in our laboratories to investigate the aqueous solution chemistry of organotin(IV) compounds in different ionic media and at different ionic strengths (Cannizzaro et al, 1998;De Stefano et al, 1996a, 1997a, 1999b, 1999c, 1999dFoti et al, 1999), in order to draw a speciation picture for these compounds in natural fluids. In this paper we report comprehensive results on the inorganic speciation of monomethyl-, dimethyl and trimethyltin(IV) cations in seawater by considering their interactions with major (chloride and sulphate) and minor (carbonate and fluoride) anionic components.…”

Thermodynamic and spectroscopic study for the interaction of dimethyltin(IV) with L–cysteine in aqueous solution

“…This work represents a further step in our systematic investigations on the speciation of mono-, di-and tri-methyltin(IV) cations and their interactions with several carboxylic ligands in aqueous solution [22][23][24][25][26][27][28][29][30]. In this paper we give a complete picture of the thiolic group influence on the interaction of dimethyltin(IV) cation with cys by determining thermodynamic parameters by potentiometric and calorimetric measurements, describing the speciation in aqueous solution and confirming findings by spectroscopic (UV and 1 H NMR) investigations.…”

Speciation of Phytate Ion in Aqueous Solution. Trimethyltin(IV) Interactions in Self Medium

“…This percentage increases in both Figures 2 and 3 in more alkaline pH values, where the formation of neutral hydrolytic (CH 3 ) 3 SnOH 0 ( Figure 1) is so strong that makes tmt to be unavailable for complexation (as observed for other organotin(IV) and several other ligands). [16][17][18][19][20]22,23,[28][29][30][31][32][33][34][35][36][37][38] Taking into account all the species proposed in the speciation models reported in Table 4, we obtained an empirical equation to calculate average formation constants of the trimethyltin(IV)-phytate system; the empirical equation is expressed as follows: …”