Organic chemistry is the branch of chemistry that deals with the structure, properties, composition, reactions, and preparation of carbon-containing compounds, which include not only hydrocarbons but also compounds with any number of other elements, including hydrogen (most compounds contain at least one carbon–hydrogen bond), nitrogen, oxygen, halogens, phosphorus, silicon, and sulfur. This field of chemistry was traditionally limited to compounds produced by living organisms but has been broadened to include human-made substances such as plastics. The range of application of organic compounds is enormous and includes the pharmaceutical, chemical, materials science, and agricultural industries, among others.
The versatility of carbon makes it the backbone of organic chemistry. Carbon atoms can form four covalent bonds with other atoms, leading to a diverse array of compounds. A single carbon atom can bond with other carbon atoms forming chains or rings, thus creating the skeleton or framework of an organic molecule. These carbon chains can be modified by the inclusion of other elements called functional groups, which determine the properties and reactions of the molecule.
Hydrocarbons are the simplest organic compounds, composed exclusively of carbon and hydrogen. They are categorized into alkanes, alkenes, alkynes, and aromatic hydrocarbons based on their structure and types of carbon-carbon bonds.
Functional groups are specific groups of atoms within molecules that have certain characteristic properties regardless of the other atoms present in a molecule. They are key to understanding the chemistry and reactivity of organic molecules. Some common functional groups include:
Isomers are compounds with the same molecular formula but with different structural arrangements, and thus, different properties. Isomerism is a critical concept in organic chemistry because it explains how molecules with the same atoms can have different structures and properties. There are two main types of isomerism: structural (or constitutional) isomers, which differ in the covalent arrangements of their atoms, and stereoisomers, which have the same covalent arrangements but differ in the spatial arrangements of their atoms. An example of structural isomerism can be seen with butane \(C4H{10}\), which has two isomers: n-butane and isobutane. Stereoisomerism includes enantiomers, which are mirror images of each other and cannot be superimposed, like left and right hands.
Organic reactions are chemical reactions involving organic compounds. The basic types of organic reactions include:
Organic chemistry is a vast and fascinating field that plays a crucial role in understanding the chemical makeup and processes of living organisms as well as in the development of new materials and pharmaceuticals. By understanding the basic concepts of organic chemistry, such as the structure and reactivity of organic molecules, hydrocarbons, functional groups, isomerism, and organic reactions, one gains insight into the chemical basis of life and the synthesis of novel compounds.
