Nomenclature Of Organic Compounds

Introduction

The International Union of Pure and Applied Chemistry (IUPAC) organic chemistry nomenclature is a technique of classifying organic chemical compounds. In the Organic Chemistry Nomenclature, it is published as a reference.

In an ideal world, every conceivable organic component would have a name that could be used to generate a structural formula that was obvious. The International Union of Pure and Applied Chemistry (IUPAC) nomenclature is also used in inorganic chemistry.

Although the formal recommendations for naming IUPAC are not always followed in reality, they are usually followed when a compound needs to be given an unambiguous and absolute definition. This is done to prevent cumbersome and boring names in everyday communication. In certain cases, IUPAC nomenclature is less complicated than previous terms, such as ethanol, which is used rather than ethyl alcohol.

Trivial Nomenclature System

The Trivial Nomenclature system names organic compounds in a non-systematic manner, as opposed to other systems. In the case of writing the trivial name of compounds, there is no set of recommendations that may be used to write the naming. Using this strategy, the names of organic substances are made shorter and easier to remember. Phenol, acetic acid, and toluene are examples of organic compounds. It is frequently the case that the names of compounds designated using trivial nomenclature are substantially shorter and simpler than the names of compounds defined using the matching IUPAC nomenclature. It is as a result of this that this system is still in use today. Eg. A carboxylic acid that is widely found in tamarind according to the trivial system, tartaric acid is one such carboxylic acid. Tartaric acid would be designated by the International Union of Pure and Applied Chemistry as 2,3-dihydroxy-1,4-butanedioic acid.

There are certain disadvantages to using the Trivial Nomenclature System.

Some of the flaws with the trivial system of naming organic compounds are listed in the following section:

It is possible for a single chemical to have several innocuous names. An example of this can be found in the alternate names for Phenol, which include names such as hydroxybenzene and carbolic acid, among others.

The Trivial nomenclature system is confined to only a few compounds in each specialised group, which makes it a poor choice for many applications.

Consider the following example: the first two members of the carboxylic acid group are known by the innocuous names of formic acid and acetic acid respectively. Carboxylic acids having a higher number of atoms, on the other hand, do not have easily recognisable names.

There is no specific set of guidelines for the nomenclature of complex compounds in the trivial system, and there is no such set of guidelines.

Nomenclature of Organic compound

The selection and subsequent naming of a parent structure are required for the establishment of a systematic name for an organic compound. Prefixes, infixes, and, in the case of a parent hydride, suffixes can be added to this basic name to indicate precisely the structural modifications that were made in order to construct the compound in question from the parent structure. In contrast to such systematic names, there exist traditional names that are extensively used both in industry and academic circles and can be found in both formal and informal settings. Acetic acid, benzene, and pyridine are just a few examples. This is why traditional names are kept in use when they meet the requirements of utility and when they conform to the overall pattern of systematic nomenclature.

A significant new idea is proposed, as is the concept of preferred IUPAC names, which is then implemented in a methodical manner. Until date, the nomenclature defined and approved by the International Union of Pure and Applied Chemistry (IUPAC) has placed a strong emphasis on the formation of clear names that are consistent with the historical development of the field.

IUPAC Nomenclature

According to the International Union of Pure and Applied Chemistry (IUPAC) Guidelines, the nomenclature of compounds must follow the following steps:

The Longest Chain Rule states that the parent hydrocarbon must be identified and named before any other hydrocarbons can be used. There are many different shapes and sizes of carbon chains, but the parent chain that belongs to the compound in question is normally the longest chain of carbon atoms, whether it be a straight chain or any other shape.

It is necessary to number the carbon atoms belonging to the parent hydrocarbon chain using natural numbers, starting from the end, with the lowest number assigned to the carbon atom that is carrying the substituents. The lowest set of locants must be numbered using natural numbers, starting with one and progressing clockwise.

Several instances of the same substituent: Prefixes such as di, tri, and so on are used to denote the total number of instances of the same substituent in the provided organic compounds, indicating that the substituent occurs multiple times.

Separate naming conventions for distinct substituents: In organic compounds containing numerous substituents, the relevant substituents are placed in the IUPAC nomenclature of organic compounds in alphabetical order of their names.

Various substituents that are present at the same locations are given different names: When two different substituent groups are present at the same position in an organic compound, the substituents are called in ascending alphabetical order to distinguish them from one another.

In the case of organic compounds with branched structures, complex substituents must be identified by the name substituted alkyl groups, with the carbon connected to that group denoted by the number one. In the IUPAC nomenclature of the related compounds, these branching and complicated substituents must be put in brackets to indicate their presence.

The following is the format for the IUPAC Name of the Compound:

 Prefix + Root + Primary suffix + Secondary Suffix

1. Root

The total number of carbon atoms contained in the compound’s longest carbon chain is represented by the word root (or root node). For example, the term ‘Meth’ refers to a chain that contains one carbon atom, whereas the term ‘Pent’ refers to a chain that has five carbon atoms.

2. Suffix

In IUPAC nomenclature, the suffix is usually a functional group belonging to the molecule that comes after the root of the name and is followed by the suffix. Further, it can be classified into the following categories.

A Primary Suffix is a suffix that is written immediately after the word root, such as in the instance of alkanes, where the suffix is ‘ane’, and is written immediately after the word root.

It is a secondary suffix, which is written after the primary suffix and usually comes after the hyphen. For example, compounds with an alkane and an alcohol group attached to them will be referred to as alkanols, with the suffix ‘ol’ indicating that the alcohol group is a secondary suffix.

As a result of these standards, the suffix of a compound can be written as a component of the IUPAC name of the compound in question.

3. Prefix

Prefixes are appended to the end of the IUPAC nomenclature before the root of the compound. A prefix is quite valuable since it indicates the presence of side chains or substituent groups in an organic molecule, which is very important. Prefixes such as these also provide information on the cyclic or acyclic nature of the compounds under consideration.

• Primary prefixes are used to indicate whether a given chemical is cyclic or acyclic in nature. For example, the prefix ‘cyclo’ is used to denote cyclic compounds, such as cyclopropane.
• Secondary prefixes are used to indicate the presence of side chains or substituent groups in the compound. An example of these types of prefixes would be the ‘CH3’ group, often known as the methyl group, which is found in many organic compounds.

As a result, prefixes in the International Union of Pure and Applied Chemistry nomenclature can be roughly divided into primary and secondary prefixes.

Conclusion

Chemonomenclature’s major job is to ensure that no confusion arises when a chemical name is spoken or written because it refers to more than one chemical compound; hence, each chemical name should relate to a single substance. Molecular compounds are named with the first element first and then the second element by using the stem of the element name plus the suffix -ide to denote the first element and the second element, respectively. When describing the number of atoms in a molecule, numerical prefixes are employed to specify that number.