cage hydrocarbon

(organic chemistry) A compound composed of only carbon and hydrogen atoms that contains three or more rings arranged topologically so as to enclose a volume of space; in general, the space within a cage hydrocarbon is too small to accommodate even a proton.

A compound that is composed of only carbon and hydrogen atoms and contains three or more rings arranged topologically so as to enclose a volume of space. In general, the “hole” within a cage hydrocarbon is too small to accommodate even a proton. The carbon frameworks of many cage hydrocarbons are quite rigid. Consequently, the geometric relationships between substituents on the cage are well defined. This quality makes these compounds exceptionally valuable for testing concepts concerning bonding, reactivity, structure-activity relationships, and structure-property relationships. See also Chemical bonding.

The carbocyclic analogs of the platonic solids that are tenable are tetrahedrane (structure 1, where X = −H), cubane (2), and dodecahedrane. See also Alicyclic hydrocarbon.

An unsubstituted prismane has the general formula of (CH)_n, and the carbon atoms are located at the corners of a regular prism. Prismane (3), cubane (2), pentaprismane, and hexaprismane are the simplest members of this family of cage hydrocarbons.

The monomer of the diamond carbon skeleton is adamantane (4, where X = −H).

Amantadine (4, where X = −NH₂) was developed commercially as the first orally active antiviral drug for the prevention of respiratory illness due to influenza A2-Asian viruses.

The other simple diamondoid hydrocarbons are diamantane and triamantane.

Organic chemists have prepared a wide variety of cage hydrocarbons that do not occur in nature. Among these compounds are triasterane (5), iceane or wurtzitane, and pagodane.