Aromatic Compounds Essay

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Think about these substances: mothballs and cinnamon. Both of these have a strong and unique smell. This is because these substances are made of aromatic compounds. In this lesson, we will learn all about aromatic compounds.

!!!Aromatic Compounds

Let’s think of substances that have are fragrant or have distinct odor like perfume, vanilla and cinnamon. All these substances are known to have a distinct smell and are fragrant, or we can say aromatic. The smell is because these substances are made of aromatic compounds.

Perfume Vanilla Extract Cinnamon
These Substances are Made of Aromatic Compounds

__Aromatic compounds__ are substances that consist of one or more rings in its chemical structure that contain alternating …show more content…

Here, we can see that they contain rings with alternating single and double bonds in their chemical structure.

Toluene Naphthalene
Examples of Aromatic Compounds

In the ring, the electrons are delocalized. When we say ‘’delocalized electrons’’, it means that these electrons are not attached on a fixed atom. The electrons are spread out over the ring, and they can also be described as “floating” around the ring. In benzene, for instance, the two structures show that the double bonds can be moved about the ring because the electrons are delocalized within the ring. This is why alternating double bonds in the ring can also be illustrated as a circle, as shown below.

Benzene has delocalized electrons in the ring

The ring structure of an aromatic compound must be __coplanar, so this means that the atoms involved in the ring are on the same plane. Here, we can see that the carbon (gray) and hydrogen (white) atoms are all on the same plane.

Top View Side View

Benzene has a coplanar …show more content…

Many aromatic compounds have an odor but there are some compounds that are aromatic but do not have a distinct smell. A compound can be classified as an aromatic compound if it has the properties we mentioned earlier, and if it follows Huckel’s Rule, which we will discuss in the next section.

!!!Huckel’s Rule: Definition and Examples

In order for a compound to be aromatic, it also must satisfy Huckel’s Rule. __Huckel’s Rule__ states that an aromatic compound must have a certain number of pi electrons. The number of pi electrons must be equal to 4n+2, where n is equal to zero or any positive integer (n = 0, 1, 2…).

What is a pi electron? A __pi electron__ are the electrons that are present in the double bonds. To check if a compound follows Huckel’s rule, first, we need to count the number of pi electrons – these are the electrons in the double bonds in the ring. In our example below, benzene, there are six pi electrons.

Counting Pi Electrons In

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