Applications of Coordination Compounds

Last Updated : 29 Nov, 2022

Chemical compounds made up of an array of anions or neutral molecules linked to a central atom by coordinate covalent bonds are known as coordination compounds. Coordination compounds are also known as coordination complexes. Ligands are the molecules or ions that are bonded to the central atom (also known as complexing agents).

Coordination Compounds

Coordination compounds are a type of compound that belongs to the complex compound class. This is due to the chemistry involved with these molecules. Transition metals have the unique ability to generate coordination complexes. This is because of the high charge-to-mass ratio and the availability of d-orbitals.

Coordination chemistry developments have produced a variety of complex chemicals that we employ in a variety of sectors. Coordination chemicals are widely used in a variety of sectors. These include naming a few, mining and metallurgy, medical sciences, and so on.

Examples of coordination compounds

Coordination complexes are found in many biological substances. There are a plethora of additional coordination molecules that play critical roles in biological processes. During these physiological activities, the bodies make and consume a large number of complex chemicals. Chlorophyll is required for photosynthesis in plants. This chlorophyll is a combination of magnesium and porphyrin. Many of the enzymes that catalyze biological processes in our bodies are coordination complexes. Carboxypeptidase is one such example. It is a coordination molecule that also functions as an enzyme. It is required to catalyze the digestive process.

Properties of Coordination Compounds

The existence of unpaired electrons that absorb light in their electronic transitions colors the coordination compounds created by the transition elements. Complexes containing Iron(II) might be green or pale green in color, whereas coordination compounds containing Iron(III) are brown or yellowish-brown in color.
Because of the presence of unpaired electrons, the related coordination complexes have a magnetic character when the coordination center is a metal.
Coordination compounds have a wide range of chemical reactivity. They can be involved in both inner-sphere and outer-sphere electron transfer reactions.
Complex compounds containing certain ligands have the ability to catalyze or stoichiometrically help in the transition of molecules.

Werner’s Theory of Coordination Compounds

Werner developed a theory in 1893 to explain the structures, production, and nature of bonding in coordination molecules. Werner's theory of coordination compounds is the name given to this hypothesis. Werner received the Nobel Prize in Chemistry in 1913 as the first inorganic chemist. He investigated a wide range of complicated chemicals derived from the interaction of cobalt chloride and ammonia. The core metals of coordination compounds have two valencies.

Primary Valency: Primary valencies are those that a metal exhibits when simple salts are formed like NaCl, CuSO₄, and so on. In current parlance, it denotes the metal's oxidation number. For example, the major valencies of Co in CoCl₃ are 3 and the oxidation state is +3. Ionizability exists for the primary valencies. These are written beyond the scope of cooperation. These are non-directional and do not offer complicated compounds in any shape. [Co(NH₃)₆]Cl₃, 3 main valencies, +3 oxidation state.
Secondary valency: Metals' secondary valency is determined by either negative ions or neutral molecules, or both. In current parlance, it denotes the metal's coordination number. Within the coordinating sphere, secondary valencies are written. These are directed in character and give the complex a definite geometry. These cannot be ionized. [Co(NH₃)₆] is an example. Cl₃ has a coordination number of 6.

Importance of Coordination Compounds

Coordination compounds, such as the FeCl₄^- ion are so named because they contain ions or molecules that are linked to, or coordinated with, a transition metal, because they are Lewis acid-base complexes, they are also known as complex ions or coordination complexes. Ligands are the ions or molecules that bind to transition-metal ions to generate these complexes. The coordination number is the number of ligands attached to the transition metal ion. A coordination complex is any of a class of chemicals with chemical structures in which a central metal atom is surrounded by nonmetal atoms or groups of atoms, known as ligands, that are chemically linked to it. Coordination compounds include vitamin B12, hemoglobin, and chlorophyll, as well as dyes and pigments, and catalysts utilized in the synthesis of organic molecules.