Principles of Coupled Reaction

A coupling reaction is termed as the combination of a spontaneous and a non-spontaneous reaction together to produce a stable reaction. However, sometimes a doubling reaction needs a catalyst to improve the functioning and the combination of the bond. Taking into consideration the combination of the coupling reaction of polymers, where the anionic and cationic reactions take place. The active sites of the polymers are bonded together to form a stable compound which is termed as copolymers. The coupling reactions are categorized into two groups: the Hetero coupling reaction and the Homo coupling reaction. Each of these coupling reactions has its distinctive properties and application in the medical and biological fields.

COUPLING REACTION:

A coupling reaction can be defined as the joining of one or more reactions together to form a new reaction. In other words, a coupling reaction is the combination of a thermodynamically favourable reaction to that with a thermodynamically favourable reaction with each other. However, sometimes our catalyst is used to provide a thermodynamic push to the reaction. Similarly, a kinetic push is provided by the enzymes that are present or intentionally infused. The coupling reaction is further categorized into two groups, hetero coupling reaction and homocoupling reaction. This reaction plays a vital role in the pharmaceutical and biological fields. Various pharmaceuticals and polymers are being manufactured under the principle of coupled reaction.

PRINCIPLE OF COUPLED REACTION:

A coupled reaction is defined as a reaction between two components which are supporting each other for carrying out the complete reaction. The basic principle of coupled reaction is that the combination of the reactions is done in such a way that one of the reactions is energetically favourable, whereas the other one is not. The term used for these two reactions used in a coupling reaction is Endergonic reactions and Exergonic reactions. Moreover, in a coupled reaction, the product of one reaction acts as a catalyst for the next reaction for the easement and the completion of the chemical reaction. 

In coupled reactions a number of energy is released and one of the most important energies is the Gibbs energy. As long as the Gibbs energy is in the negative form both the reactions can take their course.Therefore, in a coupled reaction, the product of one reaction is an intermediate linkage of the second reaction. However, a coupling reaction is categorised into two categories, Hetero coupling reaction and Homo coupling reaction.

TYPES OF COUPLING REACTION:

A coupling reaction is termed as the combination of two distinctive reactions which leads to the outcome of another stable reaction. There are two types of coupling reactions. They are:

1. Hetero coupling reaction: A Hetero coupling reaction takes place when two different types of reaction combine to form a stable reaction in the presence of a catalyst. It is also called a cross-coupling reaction. This coupling reaction is one of the basic foundations for various pharmaceutical companies.
2. Homo coupling reaction: Homo coupling reaction takes place between two similar reactions to form a stable reaction in the presence of a catalyst or enzyme. There are several examples related to homocoupling, like, the Wurtz reaction, Glaser coupling

EXAMPLES:

Coupling reactions plays a vital role in the field of pharmaceutical and biological fields. There are several examples relating to the beneficial activities of this reaction. They are:

• Coupling reaction in chemistry: 

Coupling reaction plays a vital role in organometallic chemistry. One of the basic examples of coupling reactions in the chemistry field is the reaction performed on the organotrifluoroborates [RBF3]K. This cross-coupling reaction of boron reagent takes place in the presence of a base with an organic halide. 

• A couple of reactions in biochemistry:

One of the basic examples of the coupled reaction in biochemistry is the hydrolysis of ATP. In this reaction, the adenosine triphosphate reaction generates Adenosine Diphosphate (ADP) along with an inorganic phosphate ion. The reaction consists of highly negative Gibbs energy, which shows that the reaction is a high energy reaction. ATP is responsible for the regulated metabolism of the body, and it plays a vital role in producing energy for the cell.

The ATP fills up with high energy so that they act as a catalyst for another reaction for producing a couple of reactions.

APPLICATION OF COUPLING REACTION:

The coupling reaction is the basic foundation of various pharmaceutical companies and the biological field as well. Several applications of the coupling reactions are:

1. Coupling reactions plays a vital role in the production of various pharmaceutical products.
2. Several polymers and monomers are created through the coupling reaction.
3. Suzuki coupling reaction is one the most widely used coupling reaction.

CONCLUSION:

A Coupling Reaction is termed the combination of two reactions to form a new stable reaction. In a couple of reactions, one of the reactions is concentrated to be endergonic, and the other is said to be an exergonic reaction. The basic principle of a coupling reaction is that the product of one reaction works as a catalyst for the completion of another reaction. There are two types of coupling reactions, namely, hetero coupling reactions and homo-coupling reactions. The coupling reaction plays a vital role in the biochemistry, medical as well as pharmaceutical fields. To understand the concept of the coupling reaction, one is required to have a basic knowledge of inorganic chemistry.