Functional groups

any organic compound in which the hydroxyl functional group (–OH) is bound to a saturated carbon atom

150px|alt=Aldehyde structure|thumb|class=skin-invert|Aldehyde structure

Urea, also called carbamide (because it is a diamide of carbonic acid), is an organic compound with chemical formula . This amide has two amino groups (−) joined by a carbonyl functional group (−C(=O)−). It is thus the simplest amide of carbamic acid.

oxoacid having the structure RC(=O)OH, used as a suffix in systematic name formation to denote the –C(=O)OH group including its carbon atom

130px|thumb|An ester of a carboxylic acid. R stands for [[hydrogen, halogen or organyl and R stands for any organyl group.]] In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distinctive functional group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well (e.g. amides

thumb|150px|The general structure of an ether. R and R' represent most organyl [[substituents.]]

thumb|164x164px|Primary amine In chemistry, amines (, ) are organic compounds that contain carbon–nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of electrons. Amines can also exist as heterocyclic compounds. Aniline is the simplest aromatic amine, consisting of a benzene ring bonded to an amino group. thumb|3D diagram of the aromatic compound of aniline. The light black balls are carbon atoms, and white balls are hydrogen atoms, while the nitrogen atom is the blue ball. The d

In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). A ketone derived from an alkane is an alkanone. The simplest ketone is acetone (where R and R' are methyl), with the formula . Many ketones are of great importance in biology and industry. Examples include many sugars (ketoses), many steroids, e.g., testosterone, and the solvent acetone.

group of atoms in a molecule which imparts specific chemical properties

In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid, phosphoric acid .

Nitrate is a polyatomic ion with the chemical formula . Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are soluble in water. An example of an insoluble (inorganic) nitrate is bismuth oxynitrate.

thumb|right|General structure of an amide (specifically, a carboxamide) thumb|right|Formamide, the simplest amide thumb|right|Asparagine ([[zwitterionic form), an amino acid with a side chain (highlighted) containing an amide group]]

chemical group

divalent functional group (>C=O)

Pyridine is a basic heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom . It is a highly flammable, weakly alkaline, water-miscible liquid with a distinctive, unpleasant fish-like smell. Pyridine is colorless, but older or impure samples can appear yellow. The pyridine ring occurs in many commercial compounds, including agrochemicals, pharmaceuticals, and vitamins. Historically, pyridine was produced from coal tar. As of 2016, it is synthesized on the scale of about 20,000 tons per year worldwide.

thumb|upright=0.5|right|Thiol with a sulfhydryl group.

Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting fish, due to the presence of substituted phosphine and diphosphane (). With traces of present, is spontaneously flammable in air (pyrophoric), burning with a luminous flame. Phosphine is a highly toxic respiratory poison, and is immediately dangerous to life or health at 50 ppm. Phosphine has a trigonal pyramidal structure.

thumb|upright|Tetrafluoroethane (a haloalkane) is a colorless liquid that boils well below room temperature (as seen here) and can be extracted from common [[canned air canisters by simply inverting them during use.]]

Sulfide (also sulphide in British English) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. Sulfide also refers to large families of inorganic and organic compounds, e.g. lead sulfide and dimethyl sulfide. Hydrogen sulfide (H2S) and bisulfide (HS−) are the conjugate acids of sulfide.

In chemistry, a hydride is formally the anion of hydrogen (H−), a hydrogen ion with two electrons. In modern usage, this is typically only used for ionic bonds, but it is sometimes (and has been more frequently in the past) applied to all compounds containing covalently bound H atoms. In this broad and potentially archaic sense, water (H2O) is a hydride of oxygen, ammonia is a hydride of nitrogen, etc. In covalent compounds, it implies hydrogen is attached to a less electronegative element. In such cases, the H centre has nucleophilic character, which contrasts with the protic character

thumb|class=skin-invert-image|The structure of a nitrile: the functional group is highlighted blue

In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (−O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds are classified as simple phenols or polyphenols based on the number of phenol units in the molecule. thumb|right|Phenol the simplest of the phenols thumb|right|144px|Chemical structure of salicylic acid, the [[active metabolite of aspirin]]

alkyl group derived from methane

organic compounds that contain one or more nitro functional groups

thumb|right|450px|From left to right, the above are general structures of β-lactam, a [[γ-lactam, a δ-lactam, and ε-lactam. Their common names are β-propiolactam, γ-butyrolactam, δ-valerolactam, and ε-caprolactam.]]

thumb|Generic structure of acetals

Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated.

moiety derived by the removal of one or more hydroxyl groups from an oxoacid (organic or inorganic)

any organic compound having the structure RSR (R ≠ H)

Hydroxylamine (also known as hydroxyammonia) is an inorganic compound with the chemical formula . The compound exists as hygroscopic colorless crystals. Hydroxylamine is almost always provided and used as either an aqueous solution or, more often, as one of its salts, such as hydroxylammonium sulfate, a water-soluble solid.

class of organic compounds bearing the functional group R–N=N–R′, in which R and R′ can be either aryl or alkyl

organic compound with the structure R−S(=O)₂−OH

thumb|A generic epoxide

thumb|The isocyanate functional group

thumb|right|150px|The general structure of an imine

unsaturated, organic functional group

Thiourea () is an organosulfur compound with the formula and the structure . It is structurally similar to urea (), with the oxygen atom replaced by sulfur atom (as implied by the thio- prefix). The properties of urea and thiourea differ significantly. Thiourea is a reagent in organic synthesis. Thioureas are a broad class of compounds with the formula

thumb|right|200px|Space-filling model of the cyanate anion

thumb|Chemical structure of carbamates

right|thumb|150px|Sulfoxide group

Aziridine is an organic compound consisting of the three-membered heterocycle . It is a colorless, toxic, volatile liquid that is of significant practical interest. Aziridine was discovered in 1888 by the chemist Siegmund Gabriel. Its derivatives, also referred to as aziridines, are of broader interest in medicinal chemistry.

thumb|60px|Methylene (compound)|Methylene is the simplest carbene. In organic chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The general formula is or where the R represents substituents or hydrogen atoms.

right|250x250px

thumb|150px|Structure of the nitrosamino group

\right]|caption=General resonance structure of an isocyanide

thumb|A general linear imide functional group In organic chemistry, an imide is a functional group consisting of two acyl groups bound to nitrogen. The compounds are structurally related to acid anhydrides, although imides are more resistant to hydrolysis. In terms of commercial applications, imides are best known as components of high-strength polymers, called polyimides. Inorganic imides are also known as solid state or gaseous compounds, and the imido group (=NH) can also act as a ligand.

thumb|General formula for a ketene

any chemical compound having two acyl groups bonded to the same oxygen atom

thumb|right|Ethylene glycol, a common diol

thumb|150px|The general structure of an enamine An enamine is a functional group with the formula . Enamines are reagents used in organic synthesis and are intermediates in some enzyme-catalyzed reactions.

Biuret ( ) is a chemical compound with the chemical formula . It is a white solid that is soluble in hot water. A variety of organic derivatives are known. The term "biuret" also describes a family of organic compounds with the chemical formula , where are hydrogen, organyl or other groups. Also known as carbamylurea, it results from the condensation of two equivalents of urea. It is a common undesirable impurity in urea-based fertilizers, as biuret is toxic to plants.

thumb|The general structure of a hemiacetal (left) and hemiketal (right). In organic chemistry, a hemiacetal is a functional group with the general formula , where is a hydrogen atom or an organic substituent. They generally result from the nucleophilic addition of an alcohol (a compound with at least one hydroxy group) to an aldehyde () or a ketone () under acidic conditions. The addition of an alcohol to a ketone is more commonly referred to as a hemiketal. Common examples of hemiacetals include cyclic monosaccharides. Hemiacetals have use as a protecting group and in synthesizing oxygenated

thumb|144 px|Structure of the methoxide anion. Although alkali metal alkoxides are not salts and adopt complex structures, they behave chemically as sources of . thumb|right|The structure of the methoxide ion In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organyl substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands. Alkoxides, although generally not stable in protic solvents such as water, occur widely as inte

any organic compound of the form R-O-O-R′, where R and R′ are organic residues

Azoles are a class of five-membered heterocyclic compounds containing a nitrogen atom and at least one other non-carbon atom (i.e. nitrogen, sulfur, or oxygen) as part of the ring. Their names originate from the Hantzsch–Widman nomenclature. The parent compounds are aromatic and have two double bonds; there are successively reduced analogs (azolines and azolidines) with fewer. One, and only one, lone pair of electrons from each heteroatom in the ring is part of the aromatic bonding in an azole. Names of azoles maintain the prefix upon reduction (e.g., pyrazoline, pyrazolidine). The numbering o

diazonium salts

thumb|class=skin-invert-image|right|150px|General structure of a thioester, where R and R' are organyl groups, or H in the case of R. In organic chemistry, thioesters are organosulfur compounds with the molecular structure . They are analogous to carboxylate esters () with the sulfur in the thioester replacing oxygen in the carboxylate ester, as implied by the thio- prefix. They are the product of esterification of a carboxylic acid () with a thiol (). In biochemistry, the best-known thioesters are derivatives of coenzyme A, e.g., acetyl-CoA. The R and R' represent organyl groups, or H in the

thumb|right|144px|The sulfonate ion.

any chemical compound having a chlorine atom bonded to a carboacyl group