Speciation of phytate ion in aqueous solution trimethyltin(IV) interactions in self medium

In this paper the results Of a potentiometric (ISE-[H+] glass electrode) investigation at t = 25 degrees C on the cornplexing ability of phytate towards trimethyltin(IV) (tmt) and on the acid-base properties of tmt at high metal concentration (0.050 and 0.075 mol L-1) are reported. First we determined the hydrolytic constants of tmt in aqueous solution without further addition of background salt (self medium); in these experimental conditions we verified the formation of the following hydrolytic species: tmt(OH)(0), tmt(OH)(2)(-) and the binuclear species (tmf)(2)(OH)(+). Successively, we studied the complex formation constants obtained from the interaction of phytatc anion with tmt in the same experimental conditions of hydrolytic measurements; the speciation model obtained takes into account several polynuclear species (tmtH(5)Phy(6-); tmt(2)H(5)Phy(5-); tMt(3)H(4) Phy(5-); tmt(3)H(5)Phy(4-); tmt(4)H(6)Phy(2-); tmt(5)HPhy(6-)). A comparison with literature data is reported too.