The classification of organic compounds is based on the theory of the chemical structure of A. M. Butlerov. Systematic classification is the foundation of scientific nomenclature. Thanks to it, it became possible to give a name to every previously known and new organic substance, based on the existing structural formula.
Classes of Organic Compounds
Organic substances are classified according to two main characteristics: localization and the number of functional groups in the molecule and the structure of the carbon skeleton.
The carbon skeleton is a part of the molecule that is quite stable in various chemical reactions. Organic compounds are divided into large groups, while taking into account the molecular structure of organic matter.
Acyclic compounds (fatty compounds or aliphatic compounds). These organic compounds in the structure of molecules contain a straight or branched carbon chain.
Carbocyclic compounds are substances with closed carbon chains - cycles. These bio compounds are divided into groups: aromatic and alicyclic.
Heterocyclic natural organic compounds are substances in the structure of which there are cycles formed by carbon atoms and atoms of other chemical elements (Oxygen, Nitrogen, Sulfur) by heteroatoms.
Compounds of each row (group) are divided into classes of various organic compounds. The affiliation of organic matter to a particular class is determined by the presence of certain functional groups in its molecule. For example, classes of hydrocarbons (the only class of organic substances that lack functional groups), amines, aldehydes, phenols, carboxylic acids, ketones, alcohols, etc.
To determine whether an organic compound belongs to a series and class, a carbon skeleton or carbon chain (acyclic compounds), a cycle (carbocyclic compounds), or a core (heterocyclic compounds) are isolated . Subsequently, the presence of other atomic (functional) groups in the molecule of the organic matter is determined, for example, hydroxyl — OH, carboxyl — COOH, amino group, imino group, sulfhydride group — SH, etc. A functional group or groups determine whether a biocompound belongs to a particular class, its main physical and chemical properties. It should be said that each functional group not only determines these properties, but also affects other atoms and atomic groups, at the same time experiencing their influence.
When substituting in the molecules of acyclic and cyclic hydrocarbons or heterocyclic compounds of the Hydrogen atom for various functional groups, organic compounds are obtained that belong to certain classes. We present individual functional groups that determine whether an organic compound belongs to a particular class: hydrocarbons RH, halogenated hydrocarbons R-Hal, aldehydes R-COH, ketones R1-CO-R2, alcohols and phenols R-OH, carboxylic acids R-COOH ethers - R1-O-R2, carboxylic acid halides R-COHal, esters R-COOR, nitro compounds - R-NO2, sulfonic acids - R-SO3H, organometallic compounds - R-Me, mercaptans R-SH.
Organic compounds that have one functional group in the structure of their molecules are called organic compounds with simple functions, two or more - compounds with mixed functions. Examples of organic compounds with simple functions can be hydrocarbons, alcohols, ketones, aldehydes, amines, carboxylic acids, nitro compounds, etc. Examples of compounds with mixed functions can be hydroxy acids, keto acids, and the like.
Complex bioorganic compounds occupy a special place: proteins, proteids, lipids, nucleic acids, carbohydrates, in the molecules of which there are a large number of different functional groups.