An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of compounds such as carbonates, simple oxides of carbon and cyanides, as well as the allotropes of carbon, are considered inorganic. The division between "organic" and "inorganic" carbon compounds while "useful in organizing the vast subject of chemistry...is somewhat arbitrary".

Organic chemistry is the science concerned with all aspects of organic compounds. Organic synthesis is the methodology of their preparation.

History

The name "organic" is historical, dating back to the 19th century, when it was believed that organic compounds could only be synthesized in living organisms through vis vitalis - the "life-force". The theory that organic compounds were fundamentally different from those that were "inorganic", that is, not synthesized through a life-force, was disproved with the synthesis of urea, an "organic" compound by definition of its known occurrence only in the urine of living organisms, from potassium cyanate and ammonium sulfate by Friedrich Wöhler in the Wöhler synthesis. The kinds of carbon compounds that are still traditionally considered inorganic are those that were considered inorganic before Wöhler's time; that is, those which came from "inorganic" (i.e., lifeless) sources such as minerals.Spencer L. Seager, Michael R. Slabaugh. Chemistry for Today: general, organic, and biochemistry. Thomson Brooks/Cole, 2004, p. 342. ISBN 053439969X

Classification

See Organic chemistry#Classification of organic substances

Organic compounds may contain atoms of further elements, so-called heteroatoms. Organometallic compounds constitute a further subsection, characterized by covalent bonds between organic carbon and a metal.

There is also a large number of inorganic carbon compounds to distinguish from organic compounds.

Natural compounds

An important subset of organic compounds is still extracted from natural sources because they would be far too expensive to be produced artificially. Examples include most sugars, some alkaloids and terpenoids, certain nutrients such as vitamin B₁₂, and in general, those natural products with large or stereoisometrically complicated molecules which are present in reasonable concentrations in living organisms.

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

Synthetic compounds

Many polymers, including all plastics are organic compounds.

Nomenclature