Classification and Nomenclature of Organic compounds

In chemistry, organic compounds are essentially any chemical compounds that contain carbon-hydrogen bonds. Due to carbon’s capacity to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the characteristics, reactions, and syntheses of organic compounds form the field known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exclusions (e.g., carbon dioxide), are not categorized as organic substances and are considered inorganic. Other than those just named, no consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any formal definition of an organic compound tricky. Although organic compounds make up just a small fraction of Earth’s crust, they are of great significance since all known life is reliant on organic compounds.

Classification

Organic compounds may be categorised in a variety of ways. One key contrast is between natural and synthetic compounds. Organic compounds can also be categorized or subdivided by the presence of heteroatoms, e.g., organometallic compounds, which feature bonds between carbon and a metal, and organophosphorus compounds, which feature bonds between carbon and a phosphorus.

Another distinction, depending on the size of organic compounds, distinguishes between small molecules and polymers.

Natural compounds

Natural compounds refer to those that are created by natural plants or natural animals, that have not been considerably changed by human intervention, or which survive despite human intervention. Many of these are still extracted from natural sources since they would be more expensive to generate artificially. Examples include most sugars, certain alkaloids and terpenoids, certain nutrients such as vitamin B12, and, in general, those natural products with large or stereoisometrically complex molecules present in realistic amounts in living organisms.

Further molecules of prime significance in biochemistry are antigens, carbohydrates, enzymes, hormones, lipids and fatty acids, neurotransmitters, nucleic acids, proteins, peptides and amino acids, lectins, vitamins, and fats and oils.

Synthetic compounds

Compounds that are formed by reaction of other compounds are known as “synthetic”. They may be either compounds that already are present in plants or animals or ones that do not occur naturally.

Organic synthetic or semi-synthetic chemicals make up the majority of polymers (a category that includes all plastics and rubbers).

Biotechnology

Many organic compounds—two examples are ethanol and insulin—are made industrially utilizing organisms such as bacteria and yeast. Typically, the DNA of an organism is modified to express compounds not typically produced by the organism. Many of these biotechnology-engineered chemicals did not exist in nature before.

Nomenclature Of Organic Compounds

Nomenclature denotes the system of naming of organic substances. In case of aliphatic compounds, two system of nomenclature frequently used are:

1) Trivial or common system

2) IUPAC system

Trivial or common system

Organic compounds were named after the source from which they were initially isolated.

For example

Urea got its name as the compound was initially discovered from the urine of mammals

Methyl alcohol was termed wood spirit as it could be obtained by the destructive distillation of wood.

Acetic Acid acquired its name from the acetum as it is present in vinegar.

Citric acid gets its name from the fact that it’s found in citrus fruits.

IUPAC system

To systematize the nomenclature of organic compounds, IUPAC system of nomenclature was first established in 1947.

General Principles for IUPAC Nomenclature of organic compounds

The most major characteristic of this system is that any given molecular structure has just one IUPAC name and any given IUPAC name implies only one molecular structure.

The IUPAC name of any organic compound primarily comprised of three parts

1. Word Root
2. Suffix
3. Prefix

Word Root– It specifies the number of carbon atoms contained in the parent chain (the longest possible continuous chain of carbon atoms including the functional group and numerous bonds) of the organic molecule.

Suffix – The two types of suffix are :

• Primary suffix : A primary suffix is always added to the word root to reflect whether the carbon chain is saturated or unsaturated.

If the parent chain has two, three, four or more double or triple bonds ,numerical prefixes like as di, tri ,tetra are added to the prefect primary.

• Secondary suffix : A secondary suffix is then added to the primary suffix to describe the type of the functional group present in the organic compound.

While adding the secondary suffix to primary suffix ,the terminal e of the primary suffix is omitted if the secondary suffix begins with a vowel but is kept if the secondary suffix begins with a consonant.

Prefix 

There are two types of prefixes:

1. Primary prefix : A primary prefix is used merely to distinguish cyclic from acyclic compounds. For ex: In case of carbocyclic compounds, a primary prefix ,cyclo is used right before the word root.
2. Secondary prefix : Certain groups are not regarded as functional groups but instead are viewed as substituents. These are termed secondary prefixes and are added immediately before the word roots in alphabetical sequence to denote the side chain or substituent groups.

IUPAC name of an organic compound consist of: Secondary prefix+ Primary prefix+ Primary suffix+ Secondary Suffix

Conclusion

Organic compound in chemistry is the class of chemical compounds that have carbon-hydrogen chemical bonding. Carbon has the ability to combine with other carbon atoms to form a long chain. Therefore, it creates more than 3 million chemical compounds. From a popular definition, organic chemistry is the chemistry of carbon compounds or molecules. The concept encompasses compounds like carbon monoxide, carbon dioxide, carbonates, carbon disulfide, etc. These are the kingdom of inorganic series. In learning chemistry, the definition or categorization of chemical compounds such as organic and inorganic compounds is quite difficult. Hydrocarbons (alkanes, alkenes, acetylene), aldehyde, ketone, alcohol, ether, carboxylic acid are the most frequent class of organic compounds.