Organic chemestry

Organic chemistry is the branch of chemistry that deals with the study of the structure, properties, reactions (synthesis, decomposition, etc.) of organic compounds. The study of structure determines chemical formulas based on chemical composition. The study of properties includes physical, chemical and chemical reactivity evaluation. The study of reactions includes chemical syntheses of natural products, drugs, polymers.

Among the organic compounds are hydrocarbons (compounds consisting only of carbon and hydrogen), but also a wide range of substances derived from hydrocarbons, which may also contain oxygen, nitrogen, sulfur, phosphorus, halogens or boron, as well as other elements, but in much smaller quantities. The connection with inorganic chemistry is made through organometallic chemistry, as a transitional science between inorganic and organic chemistry. Metalloids are also studied as elements in the constitution of organic compounds.

The structural diversity of organic compounds provides a wide range of applications in various fields of activity through the industrial manufacture of many commercial products (such as pharmaceuticals, petrochemicals and their derivatives, plastics and explosives). Also, organic chemistry is a connecting science, being the starting point for other sciences: organometallic chemistry, biochemistry, pharmacology, polymer chemistry, materials science, etc.


Before the 19th century, chemists believed that compounds obtained from living organisms had a so-called "life force" that distinguished them from inorganic compounds. According to the theories of vitalism (or vital force theory), chemical compounds can only form under the influence of the "vital force" in the body of organisms. During the first half of the 19th century, the first systematic studies of organic compounds were published.

In 1828, Friedrich Wöhler, the pioneer of organic chemistry, synthesized urea (carbamide), a constituent of urine, using only inorganic materials as a starting point (potassium cyanate and ammonium sulfate). This was the first time an organic compound was synthesized in the laboratory without using biological materials. This synthesis invalidated the vital force theory and indirectly vitalism.

In 1856, William Henry Perkin, while trying to obtain quinine, accidentally produced a dye that became known as aniline black/purple, the first synthetic organic dye. His discovery increased interest in organic chemistry.

Basically, the era of the pharmaceutical industry began with the development of organic chemistry and biochemistry. In the last decade of the 19th century, the foundations of this industry were laid with the discovery and manufacture of acetylsalicylic acid (also known as aspirin) by Bayer in Germany. Beginning in 1910, Paul Ehrlich and his research group developed arsphenamine (also known as Salvarsan), which was the first medicinal treatment for syphilis, and thus initiated the medical practice of chemotherapy. His studies made huge contributions to the development of antiserum for diphtheria and of other therapeutic serums.

Many of the organic reactions that were beginning to be discovered in the past were often based on luck or unexpected observations. However, in the second half of the 19th century, systematic studies on organic compounds began to appear. A demonstrative example is the development of the indigo synthesis process. The production of this dye from vegetable sources decreased from 19,000 tons in 1897 to 1,000 tons in 1914 due to the development of synthetic methods by Adolf von Baeyer. In 2002, 17,000 tons of synthetic indigo were obtained from petrochemicals.

Subsequently, methods of synthesis of more complex organic compounds began to be developed. Total syntheses of compounds identified in nature began to develop and grow in complexity up to glucose and terpineol. For example, cholesterol derivatives opened new directions to synthesize complex human hormones, and since the beginning of the 20th century compounds of great complexity, such as lysergic acid and vitamin B12, could be synthesized.


Organic chemistry can also be defined as the chemistry of hydrocarbons and their derivatives. Thus, according to the nature of the atoms that make up the molecule of an organic compound, there are two large categories: hydrocarbons and functional derivatives. The latter contain, in addition to hydrogen and carbon, an atom or a group of atoms that give the molecules specific physical and chemical properties, and is called a functional group or function. There are also special categories, such as heterocyclic compounds.


Aliphatic compounds

Saturated hydrocarbons
Unsaturated hydrocarbons

Aromatic compounds

Aromatic hydrocarbons are closed-chain molecules containing conjugated double bonds. The most well-known category of aromatic hydrocarbons are arenes, but there are other examples, such as some annulenes.

Functional derivatives

Halogenated compounds

Hydroxyl compounds: alcohols and phenols


Carbonyl compounds: aldehydes and ketones

Carboxylic acids