Biocatalyst
A biocatalyst means a biological-based catalyst that increases the rate of biological reaction or function in any biological system and induces the formation of products. Biocatalysts are generally natural enzymes and proteins. Biocatalysts are very sensitive to temperature and pH. They act only on their specific reactants for further reactions. The activities of biocatalysts can be controlled and modulated.
Example: Pepsin and Trypsin.
These biocatalysts are responsible to start and make the breakdown reaction of protein into amino acids very quickly.
Biocatalysts are used for improving the performance of detergents, processing food, allowing diagnostic laboratories, etc.
Annulene
Annulenes are completely conjugated, monocyclic hydrocarbons that contain the maximum number of alternating ring double bonds, such as benzene. It general formula of annulene is CnHn (where ‘n’ is an even number) or CnHn+1 (where n is an odd number).
The name of annulene can be represented as n-Annulene where n is an even number and n represents the number of carbon atoms present in the hydrocarbons ring.
Example: Benzene molecule is 6 Annulene, cyclobutadiene molecule is 4 Annulene, etc.
It molecule can be aromatic, anti-aromatic, or non-aromatic which can be explained by Huckel’s rule ( (4n+2)π electrons) and planarity.
Some Examples for Explanation: The name of 10-Annulene is cyclodecapentaene whose molecular formula is C₁₀H₁₀. It has 5 double bonds present in the ring.10-Annulene is not aromatic because it has a non-planar structure. As a result, steric hindrance can be found between internal hydrogens present in the compound.
[10] annulene satisfies the Huckle rule because it contains 10 π electrons.
The following rules should be satisfied for an aromatic compound:
- It should show a cyclic and planar structure.
- It must follow Huckel’s rule which means that the cyclic ring must show (4n+2) π electrons, where n is an integer.
[10] annulene does not accomplish all the above characteristics since the planarity and stability of the structure are disturbed by the steric influence of internal hydrogens in the compound. So it can be said that though [10] annulene is cyclic and satisfies Huckel’s rule, it is a non-aromatic compound for the absence of a planar structure.
8-Annulene has less strength due to the presence of 8π electrons and is unable to meet Huckle’s rule. It is a nonaromatic compound and the presence of various types of ring strain destabilizes an all-planar geometry in this compound. As a result, it cannot adopt the necessary planar configuration like aromatic compounds.
14- Annulene has much strength due to the presence of 14π electrons, and planarity and is able to meet Huckle’s rule. So It is an aromatic compound. This molecule has the absence of various types of ring strain and creates stability in an all-planar geometry in this compound. It can adopt the necessary planar configurations.
