Structural and Spectroscopic Studies on the Interactions of ortho-Phenylenediamine and Li+, Na+, Mg2+, or Ca2+ Ions

The coordinative interactions of o-phenylenediamine and alkali or alkaline earth metals like Li+, Na+, Mg2+, or Ca2+, were investigated by X-ray structural analyses and IR, UV–vis, and 1H NMR spectroscopies. These studies revealed that the coordinative interactions of o-phenylenediamine with metal ions through amino groups depend on the ratio of the charge and the ionic radius of the metal ions both in the solid state and in THF solution.