Chelating Tendencies of Some N-(2-Acetyl-1,3-Indandione) Trialkyl Ammonium Iodides with Transition Metal Ions

The ligands T.P.A.I.* and T.B.A.I.** have been synthesised and their dissociation constants are 1.738 · 10⁻¹⁰ and 1.412 · 10⁻⁸ respectively. The potentiometric studies show that these reagents form 1 : 1 complex with copper(II) and iron(II). The stability constants of copper complex and iron complex with T.P.A.I. are 6.43 and 6.51 respectively and for T.B.A.I. 4.36 and 4.24 respectively. The free energy of complex formation at 25°C are 8.76 Kcal/mole and 8.87 Kcal/mole for Cu (II)-T.P.A.I. and Fe (II)-T.P.A.I. respectively, whereas the free energy of the Cu (II)-T.B.A.I. and Fe(II)-T.B.A.I. are 5.94 Kcal/mole and 5.78 Kcal/mole respectively.