In chemistry, a parent structure is the structure of an unadorned ion or molecule from which derivatives can be visualized.[Several examples of parent structures are illustrated in ] Parent structures underpin systematic nomenclature and facilitate classification. Fundamental parent structures have one or no 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.
File:Benzene circle.png|Benzene is the parent.
File:Toluene-vec.svg|Toluene is a derivative of benzene.
File:Porphyrin.svg|Porphine is the parent of porphyrins.
File:PPIXtransH.png|Protoporphyrin IX is a natural derivative of the parent porphine.
File:H2octaethylporphyrin.png|Octaethylporphyrin is a synthetic derivative of the parent porphine.
IUPAC definitions
According to the International Union of Pure and Applied Chemistry, the concept of parent structure is closely related to or identical to
parent compound,
parent name, or simply
parent.
Organic parents
These species consist of an unbranched chain of
skeletal formula atoms, or consisting of an unsubstituted
cyclic compound or polycyclic ring system.
[ Preferred IUPAC Names Provisional Recommendation september 2004 Chapter 1 Par. P-12.1] Parent structures bearing one or more
that are not specifically denoted by a suffix are called
functional parents.
[ Preferred IUPAC Names Provisional Recommendation september 2004; Par. P-34] Names of parent structures are used in IUPAC nomenclature as basis for systematic names.
Hydride parents
A
parent hydride is a parent structure with one or more
hydrogen atoms. Parent hydrides have a defined standard population of hydrogen atoms attached to a skeletal structure. Parent hydrides are used extensively in organic nomenclature, but are also used in inorganic chemistry.
[ Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005 (Red Book) Par. IR-6 Parent Hydride Names and Substitutive Nomenclature - Full text PDF]
File:Monophosphan.svg|Phosphine is the parent of phosphines.
File:Phenylphosphine-2D-skeletal.png|Phenylphosphine is a derivative of the parent phosphine.
File:TPPTS.png|tppts is a derivative of the parent phosphine.
See also
