In chemistry, a parent structure is the structure of an unadorned ion or

molecule A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bio ...

from which

derivatives The derivative of a function is the rate of change of the function's output relative to its input value. Derivative may also refer to: In mathematics and economics *Brzozowski derivative in the theory of formal languages *Formal derivative, an ...

can be visualized. Parent structures underpin systematic nomenclature and facilitate classification. Fundamental parent structures have one or no

functional group 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 res ...

s and often have various types of symmetry.

Benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen ato ...

() 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 A substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. (In organic chemistry and biochemistry, the terms ''substituent'' and '' functional group'', as well as '' ...

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,

is the parent. File:Toluene-vec.svg,

Toluene Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon. It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) ...

is a derivative of benzene. File:Porphyrin.svg, Porphine is the parent of porphyrins. File:PPIXtransH.png,

Protoporphyrin IX Protoporphyrin IX is an organic compound, classified as a porphyrin, that plays an important role in living organisms as a precursor to other critical compounds like heme (hemoglobin) and chlorophyll. It is a deeply colored solid that is not sol ...

is a natural derivative of the parent porphine. File:H2octaethylporphyrin.png ,

Octaethylporphyrin Octaethylporphyrin (H2OEP) is an organic compound that is a relative of naturally occurring heme pigments. The compound is used in the preparation of models for the prosthetic group in heme proteins. It is a dark purple solid that is soluble in ...

is a synthetic derivative of the parent porphine.

IUPAC definitions

According to the

International Union of Pure and Applied Chemistry The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...

, 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 A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...

atoms, or consisting of an unsubstituted monocyclic or polycyclic ring system.''Preferred IUPAC Names Provisional Recommendation''
september 200
Chapter 1
Par. P-12.1 Parent structures bearing one or more

s that are not specifically denoted by a suffix are called functional parents. 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 Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

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 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 rotti ...

is the parent of phosphines. File:Phenylphosphine-2D-skeletal.png,

Phenylphosphine Phenylphosphine is an organophosphorus compound with the chemical formula C6H5PH2. It is the phosphorus analog of aniline. Like other primary phosphines, phenylphosphine has an intense penetrating odor and is highly oxidizable. It is mainly used a ...

is a derivative of the parent phosphine. File: TPPTS.png , 3,3′,3′′-Phosphanetriyltris(benzenesulfonic acid) trisodium salt is a derivative of the parent phosphine.

References

{{Reflist Chemical nomenclature

IUPAC definitions

Organic parents

Hydride parents

See also

References