Parent Hydrides and their Derived Substituent Groups

R-2.0 Introduction

A "parent hydride" (see R- is the structure which is named before the addition of affixes denoting substituents to yield the name of a specific compound. Its name is understood to signify a definite population of hydrogen atoms attached to a skeletal structure. Acyclic parent hydrides are always unbranched, for example pentane and trisilane; although a few trivial names for branched acyclic hydrocarbons are retained (see R-9.1, Table 19(a)), their use for naming substitutive derivatives is not recommended. Cyclic parent hydrides are usually either fully saturated, for example, cyclopentane, cyclotrisiloxane, azepane, bicyclo[2.2.2]octane, and spiro[4.5]decane, or fully unsaturated, i.e., they contain the maximum number of noncumulative double bonds, for example, pyridine, 1,3-oxazole, 1H-phenalene, phenanthroline, and benzo[a]anthracene. Also, there are parent hydrides that are partially saturated, for example, 1,4-dihydro-1,4-ethanoanthracene and spiro[1,3-dioxane-2,1'-[1H]indene], and that are combinations of cyclic and saturated acyclic structures having retained trivial names (see R-9.1, Table 19(a)).

See Also:
R-2.1 Mononuclear Hydrides
R-2.2 Acyclic Polynuclear Hydrides
R-2.3 Monocyclic Hydrides
R-2.4 Polycyclic Parent Hydrides
R-2.5 Substituent Prefix Names Derived from Parent Hydrides

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