*5.2.4 Spectrophotometric method*

*5.1.2 Distribution method*

*5.1.3 Ion exchange method*

*5.1.4 Electrometric techniques*

*5.1.5 Potentiometric methods*

*5.1.6 Polarographic method*

**5.2 Other methods**

*5.2.2 Freezing technique*

*5.2.3 Biological method*

**54**

*5.2.1 Rate method*

and carbon tetrachloride, benzene, etc.

*Stability and Applications of Coordination Compounds*

and Zn(II) with amino acid complex formation.

useful for protonated and nonprotonated ligands.

To determine the solubility constant, it involves the distribution of the ligands or any complex species; metal ions are present in two immiscible solvents like water

In this method metal ions or ligands are present in solution and on exchanger. A solid polymers containing with positive and negative ions are ion exchange resins. These are insoluble in nature. This technique is helpful to determine the metal ions in resin phase, liquid phase, or even in radioactive metal. This method is also helpful to determine the polarizing effect of metal ions on the stability of ligands like Cu(II)

At the equilibrium free metal and ions are present in the solution, and using the different electrometric techniques as described determines its stability constant.

This is the graphic method used to determine the stability constant in producing metal complex formation by plotting a polarograph between the absences of substances and the presence of substances. During the complex formation, the presence

If a complex is relatively slow to form and also decomposes at measurable rate, it

This involves the study of the equilibrium constant of slow complex formation

This method is based on the study of the effect of an equilibrium concentration

reactions. The use of tracer technique is extremely useful for determining the concentrations of dissociation products of the coordination compound.

of some ions on the function at a definite organ of a living organism. The

of metal ions produced a shift in the half-wave potential in the solution.

is possible, in favorable situations, to determine the equilibrium constant.

This method is based upon the titration method or follows its principle. A stranded acid-base solution used as titrate and which is titrated, it may be strong base or strong acid follows as potentiometrically. The concentration of solution using 10<sup>3</sup> M does not decomposed during the reaction process, and this method is

The solution of 25 ml is adopted by preparing at the 1.0 � <sup>10</sup>�<sup>5</sup> M ligand or 1.0 � <sup>10</sup>�<sup>5</sup> M concentration and 1.0 � <sup>10</sup>�<sup>5</sup> M for the metal ion:

The solutions containing the metal ions were considered both at a pH sufficiently high to give almost complete complexation and at a pH value selected in order to obtain an equilibrium system of ligand and complexes.

In order to avoid modification of the spectral behavior of the ligand due to pH variations, it has been verified that the range of pH considered in all cases does not affect absorbance values. Use the collected pH values adopted for the determinations as well as selected wavelengths. The ionic strengths calculated from the composition of solutions allowed activity coefficient corrections. Absorbance values were determined at wavelengths in the range 430–700 nm, every 2 nm.
