Coordination compounds, such as the rhodium complex [(Ph₃P)₃RhCl], known as the Wilkinson catalyst, serve as catalysts in industrial processes. This complex is used for the hydrogenation of alkenes.

Chlorophyll, responsible for photosynthesis, is a coordination compound of magnesium. Hemoglobin, the oxygen carrier in blood, is a coordination compound of iron. Vitamin B₁₂, vital for combating pernicious anemia, is a coordination compound of cobalt.

Extraction processes for metals like silver and gold involve complex formation, such as the formation of [Au(CN)₂]⁻ in the presence of cyanide. Purification of metals, as seen in the case of nickel, involves converting impure nickel to [Ni(CO)₄], which is ...

The hardness of water is determined by titration with Na₂EDTA. Calcium (Ca²⁺) and magnesium (Mg²⁺) ions form stable complexes with EDTA, allowing for their selective estimation based on the difference in the stability constants of their complexes.

Coordination compounds are essential in qualitative and quantitative chemical analysis. Metal ions react with ligands, forming coordination entities, which serve as the basis for detection and estimation. Reagents like EDTA, DMG, a–nitroso–b–naphthol, and cupron are commonly used.