Classification of Organic Compounds based on Functional Group

The functional group is the part of a molecule that influences its chemical characteristics. Every organic molecule’s chemistry, regardless of size or complexity, is defined by the functional group it contains.

Organic compounds are categorized as follows based on their functional group:

Hydrocarbons

Hydrocarbons are organic compounds that consist of carbon and hydrogen atoms only. They are the simplest and most abundant organic compounds found in nature and serve as the building blocks for more complex organic molecules. Hydrocarbons are classified into two main groups that are:

• Aliphatic Hydrocarbons
  • Saturated Hydrocarbons (contain only single bonds between carbon atoms)
    • Alkanes
  • Unsaturated Hydrocarbons (contain one or more double or triple bonds between carbon atoms)
    • Alkenes
    • Alkynes
• Aromatic Hydrocarbons
  • Arenes

Learn more about Functional Groups.

Compounds Containing Halogen

Organic halides or organohalides or simply halogenated compounds, are those organic compounds that contain halogen atoms such as fluorine, chlorine, bromine, or iodine. These compounds can be classified further:

• Alkyl Halides (R-X)
• Aryl Halides (Ar-X)

Learn more about Halogen.

Compounds Containing Oxygen

As carbon and hydrogen are the most abundant elements in the

• Alcohol (R-OH)
• Phenol (Ar-OH)
• Aldehyde (R-CHO)
• Ether (R-O-R)
• Carboxylic Acid (R-C(=O)-OH)

Carboxylic Acid Derivatives 

Carboxylic acid derivatives are a class of organic compounds that are structurally related to carboxylic acids. They contain a carbonyl group (C=O) bonded to a heteroatom, such as oxygen, nitrogen, or sulfur. 

• Ketone (R-C(=O)-R)
• Ester (R-COOR’).
• Amides (R-CO-NR’R”)
• Acid Halides (R-CO-X)
• Anhydride (R-C(=O)-O-C(=O)-R’)

Compounds Containing Nitrogen

Nitrogen is the seventh most abundant element in the universe and is present in a wide range of compounds, including amino acids, DNA, and proteins thus compounds containing nitrogen are a diverse and essential class of organic compounds. Some compounds containing nitrogen are:

• Amines (R-NH₂)
• Cyanide or Nitrile (R-C≡N)
• Nitro Compounds (R-NO₂)
• Imines (R-C=N-R’)

Learn more about Nitrogen.

Compounds Containing Sulfur

Sulfur-containing compounds are molecules that contain one or more sulfur atoms in their chemical structure. Sulfur is a non-metallic element with the atomic number 16 and is found in many minerals and organic materials. Some organic compounds containing Sulfur are:

• Thiols (-SH)
• Sulfides or Thioethers (R-S-R’)
• Sulfoxides (R-S(=O)-R’)
• Sulfones (R-S(=O)₂-R’)
• Thiocyanates (R-S-C≡N)

Note: In above table R – Represents Alkyl group and Ar – represents Aryl group.

Read More,

• Organic Chemistry
• Saturated and Unsaturated Hydrocarbons
• IUPAC Nomenclature

Organic compounds are defined as chemical compounds which contain carbon atoms linked with other elements through simple covalent bonds. These elements could be connected by single covalent bonds, double covalent bonds, or triple covalent bonds. In other words, we can say that all organic compounds contain carbon as their central atom. We must note that all compounds containing carbon are not considered organic compounds, such as carbonates(-CO₃), bicarbonates(-HCO₃), etc are carbon-containing compounds but not organic. Whereas we can say with surety that all organic compounds contain carbon atoms but vice versa is not true.

In this article, we will learn about organic compounds and their various classification based on bonds, functional groups, and structure. As there are millions of organic compounds and studying them individually is not possible. Therefore, the classification of organic compounds is required. So, let’s start learning about Organic Compounds and their classification.