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 degreesC on the complexing 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 (tmt)2(OH)(+). Successively, we studied the complex formation constants obtained from the interaction of phytate anion with tmt in the same experimental conditions of hydrolytic measurements; the speciation model obtained takes into account several polynuclear species (tmtH5Phy(6-); tmt2H5Phy(5-); tmt3H4Phy(5-); tmt3H5Phy(4-); tmt4H6Phy(2-); tmtsHPhy(6-)). A comparison with literature data is reported too.
Crea
Francesco
F
Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Università di Messina, Salita Sperone, 31, I-98166 Messina (Vill. S. Agata), Italy.
Crea
Pasquale
P
Milea
Demetrio
D
Porcino
Nunziatina
N
Sammartano
Silvio
S
D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D010833:Phytic Acid / Q000737:chemistry*; D011199:Potentiometry; D012996:Solutions / Q000737:chemistry; D014298:Trimethyltin Compounds / Q000737:chemistry*
D012996:Solutions; D014298:Trimethyltin Compounds; C046488:trimethyltin; D010833:Phytic Acid