Determination of the stability constants of the Mo(VI) complex with iminodiacetic acid in different sodium perchlorate aqueous solutions

The stability of molybdenum(VI) complex formed by iminodiacetic acid(IDA) has been studied at 25°C, pH = 6.0, and different ionic strengths ranging from (0.3 to 1.0) mol dm−3 of sodium perchlorate. A combination of potentiometric and spectrophotometric techniques have been used based on the continuous variations method. According to our investigations, the metal-to-ligand ratio is 1: 1. The Solver, Microsoft Excel 2000 powerful optimization package, has been used to perform non-linear least-squares curve fitting. In order to obtain better consistency between the experimental and calculated results, two empirical parameters have been introduced in a Debye-Huckel-type equation. This equation enables us to calculate the values of stability constants in the desired range of ionic strength.