In chemical nomenclature, a preferred IUPAC name (PIN) is a unique name, assigned to a chemical substance and preferred among the possible names generated by IUPAC nomenclature. The "preferred IUPAC nomenclature" provides a set of rules for choosing between multiple possibilities in situations where it is important to decide on a unique name. It is intended for use in legal and regulatory situations.
Preferred IUPAC names are applicable only for organic compounds, to which the IUPAC has the definition as compounds which contain at least a single carbon atom but no alkali, alkaline earth or transition metals and can be named by the nomenclature of organic compounds(see below). Rules for the remaining organic and inorganic compounds are still under development. The concept of PINs is defined in the introductory chapter (freely accessible) and chapter 5 of the "Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013", which replace two former publications: the "Nomenclature of Organic Chemistry", 1979 (the Blue Book) and "A Guide to IUPAC Nomenclature of Organic Compounds, Recommendations 1993". The full draft version of the PIN recommendations ("Preferred names in the nomenclature of organic compounds", Draft of 7 October 2004) is also available.
A preferred IUPAC name or PIN is a name that is preferred among two or more IUPAC names. An IUPAC name is a systematic name that meets the recommended IUPAC rules. IUPAC names include retained names. A general IUPAC name is any IUPAC name that is not a "preferred IUPAC name". A retained name is a traditional or otherwise often used name, usually a trivial name, that may be used in IUPAC nomenclature.
Since systematic names often are not human-readable a PIN may be a retained name. Both "PINs" and "retained names" have to be chosen (and established by IUPAC) explicitly, unlike other IUPAC names, which automatically arise from IUPAC nomenclatural rules. Thus, the PIN is sometimes the retained name (e.g., phenol and acetic acid, instead of benzenol and ethanoic acid), while in other cases, the systematic name was chosen over a very common retained name (e.g., propan-2-one, instead of acetone).
A preselected name is a preferred name chosen among two or more names for parent hydrides or other parent structures that do not contain carbon (inorganic parents). "Preselected names" are used in the nomenclature of organic compounds as the basis for PINs for organic derivatives. They are needed for derivatives of organic compounds that do not contain carbon themselves.A preselected name is not necessarily a PIN in inorganic chemical nomenclature.
The systems of chemical nomenclature developed by the International Union of Pure and Applied Chemistry (IUPAC) have traditionally concentrated on ensuring that chemical names are unambiguous, that is that a name can only refer to one substance. However, a single substance can have more than one acceptable name, like toluene, which may also be correctly named as "methylbenzene" or "phenylmethane". Some alternative names remain available as "retained names" for more general contexts. For example, tetrahydrofuran remains an unambiguous and acceptable name for the common organic solvent, even if the preferred IUPAC name is "oxolane".
The nomenclature goes:
The following are available, but not given special preference:
The number of retained non-systematic, trivial names of simple organic compounds (for example formic acid and acetic acid) has been reduced considerably for preferred IUPAC names, although a larger set of retained names is available for general nomenclature. The traditional names of simple monosaccharides, α-amino acids and many natural products have been retained as preferred IUPAC names; in these cases the systematic names may be very complicated and virtually never used. The name for water itself is a retained IUPAC name.
In IUPAC nomenclature, all compounds containing carbon atoms are considered organic compounds. Organic nomenclature only applies to organic compounds containing elements from the Groups 13 through 17. Organometallic compounds of the Groups 1 through 12 are not covered by organic nomenclature.
In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest of the molecule's composition. This enables systematic prediction of chemical reactions and behavior of chemical compounds and the design of chemical synthesis. The reactivity of a functional group can be modified by other functional groups nearby. Functional group interconversion can be used in retrosynthetic analysis to plan organic synthesis.
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate, millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds, along with a few other exceptions, are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive.
In organic chemistry, a vinyl group is a functional group with the formula −CH=CH2. It is the ethylene molecule with one fewer hydrogen atom. The name is also used for any compound containing that group, namely R−CH=CH2 where R is any other group of atoms.
In chemical nomenclature, the IUPAC nomenclature of organic chemistry is a method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in the Nomenclature of Organic Chemistry. Ideally, every possible organic compound should have a name from which an unambiguous structural formula can be created. There is also an IUPAC nomenclature of inorganic chemistry.
In chemistry, a bicyclic molecule is a molecule that features two joined rings. Bicyclic structures occur widely, for example in many biologically important molecules like α-thujene and camphor. A bicyclic compound can be carbocyclic, or heterocyclic, like DABCO. Moreover, the two rings can both be aliphatic, or can be aromatic, or a combination of aliphatic and aromatic.
A chemical nomenclature is a set of rules to generate systematic names for chemical compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry (IUPAC).
In chemical nomenclature, the IUPAC nomenclature of inorganic chemistry is a systematic method of naming inorganic chemical compounds, as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in Nomenclature of Inorganic Chemistry. Ideally, every inorganic compound should have a name from which an unambiguous formula can be determined. There is also an IUPAC nomenclature of organic chemistry.
In organic chemistry, the tropylium ion or cycloheptatrienyl cation is an aromatic species with a formula of [C7H7]+. Its name derives from the molecule tropine from which cycloheptatriene (tropylidene) was first synthesized in 1881. Salts of the tropylium cation can be stable, even with nucleophiles of moderate strength e.g., tropylium tetrafluoroborate and tropylium bromide (see below). Its bromide and chloride salts can be made from cycloheptatriene and bromine or phosphorus pentachloride, respectively.
Azetidine is a saturated heterocyclic organic compound containing three carbon atoms and one nitrogen atom. It is a liquid at room temperature with a strong odor of ammonia and is strongly basic compared to most secondary amines.
Thioxanthene is a chemical compound in which the oxygen atom in xanthene is replaced with a sulfur atom. It is also related to phenothiazine. Several of its derivatives are used as typical antipsychotics in the treatment of schizophrenia and other psychoses.
Benzopyran is a polycyclic organic compound that results from the fusion of a benzene ring to a heterocyclic pyran ring.
The suffix -oate is the IUPAC nomenclature used in organic chemistry to form names of compounds formed from carboxylic acids. They are of two types:
In chemical nomenclature, nor- is a prefix to name a structural analog that can be derived from a parent compound by the removal of one carbon atom along with the accompanying hydrogen atoms. The nor-compound can be derived by removal of a CH
2, or CH group, or of a C atom. The "nor-" prefix also includes the elimination of a methylene bridge in a cyclic parent compound, followed by ring contraction.. The terms desmethyl- or demethyl- are synonyms of "nor-".
Deuterated benzene (C6D6) is an isotopologue of benzene (C6H6) in which the hydrogen atom ("H") is replaced with deuterium (heavy hydrogen) isotope ("D").
Quinuclidine is an organic compound and a bicyclic amine and used as a catalyst and a chemical building block. It is a strong base with pKa of the conjugate acid of 11.0. It can be prepared by reduction of quinuclidone.
Propadiene or allene is the organic compound with the formula H2C=C=CH2. It is the simplest allene, i.e. a compound with two adjacent carbon double bonds. As a constituent of MAPP gas, it has been used as a fuel for specialized welding.
Thiopyrylium is a cation with the chemical formula C5H5S+. It is analogous to the pyrylium cation with the oxygen atom replaced by a sulfur atom.
In chemistry, a parent structure is the structure of an unadorned ion or molecule from which derivatives can be visualized. Parent structures underpin systematic nomenclature and facilitate classification. Fundamental parent structures have one or no functional groups and often have various types of symmetry. Benzene is a chemical itself consisting of a hexagonal ring of carbon atoms with a hydrogen atom attached to each, and is the parent of many derivatives that have substituent atoms or groups replacing one or more of the hydrogens. Some parents are rare or nonexistent themselves, as in the case of porphine, though many simple and complex derivatives are known.
The International Union of Pure and Applied Chemistry publishes many books which contain its complete list of definitions. The definitions are divided into seven "colour books": Gold, Green, Blue, Purple, Orange, White, and Red. There is also an eighth book—the "Silver Book".
Arsonic acid is the simplest of the arsonic acids. It is a hypothetical compound, although the tautomeric arsenious acid (As(OH)3) is well established. In contrast to the instability of HAsO(OH)2, the phosphorus compound with analogous stoichiometry exists as the tetrahedral tautomer. Similarly, organic derivatives such as phenylarsonic acid are tetrahedral with pentavalent central atom.