The key difference between isomerization and aromatization is that isomerization involves the conversion of on isomer into another isomer whereas aromatization involves the conversion of an aliphatic compound into an aromatic compound.
Isomerization and aromatization are important synthesis reactions in organic chemistry. These reactions involve the conversion of an existing chemical structure into a slightly different chemical structure. In isomerization, one isomeric form converts into another isomeric form, while in aromatization, an aliphatic compound converts into an aromatic compound.
CONTENTS
1. Overview and Key Difference
2. What is Isomerization
3. What is Aromatization
4. Side by Side Comparison – Isomerization vs Aromatization in Tabular Form
5. Summary
What is Isomerization?
Isomerization is a type of chemical reaction in which one isomeric form of an organic compound converts into another isomeric form. Most chemical compounds have only one isomer; therefore, isomerization of these compounds refers to the conversion of its structure into its isomeric form. However, some chemical compounds have more than one isomeric form; then, the isomerization refers to the conversion of one isomeric form into any of its other isomeric forms. The newly formed compound (or the new isomeric form) forms with the same chemical composition but different atomic connectivity or configuration.
Figure 01: Example of Isomerization (Conversion of n-Pentane into Isopentane)
For example, the conversion of butane into isobutene is a reaction of isomerization. In this reaction, butane is a straight-chain hydrocarbon structure. However, isobutene is a branched structure. We can achieve this isomerization via the heat treatment of butane (about 100 degrees Celsius). This heat treatment is done in the presence of a suitable catalyst. Here, the atomic connectivity of the chemical compound changes. Therefore, the chemical and physical properties of the chemical compound also change.
In alkenes, the most common form of isomerization is cis-trans isomerization. In this process, the atomic connectivity doesn’t change that much because when cis isomer converts into trans isomer, only the substituent groups attached to the double bond changes. In addition to this, we can observe the isomerization process among inorganic compounds as well. In this process, the isomerization of transition metal complexes is the most common form.
What is Aromatization?
Aromatization is a chemical process where a single nonaromatic precursor converts into an aromatic system. Typically, we can achieve aromatization via dehydrogenation of an existing cyclic compound; for example, the conversion of cyclohexane into benzene. Here, a heterocyclic compound forms.
Figure 02: Aromatization
A common example for aromatization in oil refining is the dehydrogenation of naphthene. This reaction is catalyzed by platinum, and in this reaction, naphthene is converted into toluene, which is an aromatic compound.
What is the Difference Between Isomerization and Aromatization?
Isomerization and aromatization are important synthesis reactions in organic chemistry. The key difference between isomerization and aromatization is that isomerization involves the conversion of on isomer into another isomer whereas aromatization involves the conversion of an aliphatic compound into an aromatic compound. A common example of isomerization is the conversion of butane into isobutene while conversion of cyclohexane into benzene is an example for aromatization.
The following table summarizes the difference between isomerization and aromatization.
Summary – Isomerization vs Aromatization
Ib summary, isomerization and aromatization are important synthesis reactions in organic chemistry. The key difference between isomerization and aromatization is that the isomerization involves the conversion of on isomer into another isomer whereas the aromatization involves the conversion of an aliphatic compound into an aromatic compound.
Reference:
1. “Aromatization.” Wikipedia, Wikimedia Foundation, 25 Feb. 2020, Available here.
Image Courtesy:
1. “Pentane isomerization” By Hydrargyrum, based on earlier German-annotated PNG version by Mbeychok – Vector derivative of File:Pentanisomerisierung.PNG (Public Domain) via Commons Wikimedia
2. “MeC6H11toPhMe” By Smokefoot – Own work (CC BY-SA 4.0) via Commons Wikimedia