Abstract
The interaction of Cr(III), Mn(II), and Fe(III) ions with cyclodiphosphazane and thiourea monophosphazene derivatives was followed potentiometrically with the aim of determination of stability constants of (metal : ligand) 1:1 and 1:2 binary, and 1:1:1 ternary chelates at 25°C and μ = 0.1 mole dm
− 3
NaNO
3
in 10% (v/v) H
2
O-EtOH mixture. The stability of the complexes of both ligands was found to be Fe (III) > Mn(II) < Cr(III). The concentration distribution of the species formed in solution was evaluated. Binary and ternary solid complexes were prepared with the purpose of structural characterization using elemental analyses, molar conductance, IR,
1
HNMR and electronic spectra and thermogravimetric analysis. The data show that the ligands behave as neutral bidentate ligands, forming neutral chelates of monomeric nature.