What are Coordination Compounds

Coordination compounds are chemical compounds composed of an array of anions or neutral molecules linked by coordinate covalent bonds to a central atom. Coordination compounds are also known as coordination complexes. The molecules or ions that are connected to the center atom are referred to as ligands (also known as complexing agents).

Metal complexes are coordination compounds in which the central atom is a metallic element. In this type of coordination complex, the central tom is frequently a transition element. It should be noted that the coordination center is the central atom in these complexes.

Properties of Coordination Compounds

• Because unpaired electrons absorb light during electronic transitions, transition element coordination compounds are colored. For Example, Iron (II) complexes, are green or pale green in color, whereas iron(III) coordination compounds are brown or yellowish-brown in color.
• When the coordination center is a metal, the resulting coordination complexes have a magnetic property due to the presence of unpaired electrons.
• The chemical reactivity of coordination molecules varies. They have the ability to participate in both inner-sphere and outer-sphere electron transfer reactions.
• Complex compounds with specific ligands have the ability to catalyze or stoichiometrically aid in the transition of molecules.

Applications of Coordination Compounds

Coordination compounds’ unique features, make them particularly helpful in various processes and industries. Some of these coordination compound applications are listed below.

• Because of the color of coordination compounds containing transition metals, they are widely employed in industries for material coloration. In the dye and pigment industries, they are used.
• In the electroplating process, some complex molecules using cyanide as a ligand are employed. These chemicals are also beneficial in the field of photography.
• Many metals can be extracted from their ores with the use of coordination complexes. Nickel and cobalt, for example, can be recovered from their ores via hydrometallurgical procedures using coordination complex ions.

Similar to Coordination Complex, Double Salts are also formed by the combination of two or more stable compounds in a stoichiometric ratio. However, differences exist between them.

Werner’s Theory of Coordination Compounds was proposed by a Swiss Chemist Alfered Werener in 1898. Werner studied the physical, chemical, and isomeric properties of several coordination compounds and postulated some theories.

In this article, we will learn about, Werner’s Coordination theory, its postulates, and others in detail.