In
organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, ...
, paddlane is any member of a class of
tricyclic
Tricyclics are chemical compounds that contain three interconnected rings of atoms.
Many compounds have a tricyclic structure, but in pharmacology, the term has traditionally been reserved to describe heterocyclic drugs. Among these are antid ...
saturated hydrocarbons having two bridgehead carbon atoms joined by four
bridge
A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somethi ...
s. The name derives from a supposed resemblance of the molecule to a
paddle wheel
A paddle wheel is a form of waterwheel or impeller in which a number of paddles are set around the periphery of the wheel. It has several uses, of which some are:
* Very low-lift water pumping, such as flooding paddy fields at no more than abo ...
: namely, the rings would be the propeller's blades, and the shared carbon atoms would be its axis.
Systematically named tricyclo
'm''.''n''.''o''.''p''1,''m''+2lkanes, these compounds have been referred to as
'm''.''n''.''o''.''p''addlanes. The notation
'm''.''n''.''o''.''p''addlane means the member of the family whose rings have ''m'', ''n'', ''o'', and ''p'' carbons, not counting the two bridgeheads; or ''m'' + 2, ''n'' + 2, ''o'' + 2, and ''p'' + 2 carbons, counting them. The chemical formula is therefore C
2+''m''+''n''+''o''+''p''H
2(''m''+''n''+''o''+''p''). When ''p'' = 0, the compounds are
propellane
In organic chemistry, propellane is any member of a class of polycyclic hydrocarbons, whose carbon skeleton consists of three rings of carbon atoms sharing a common carbon–carbon covalent bond. The concept was introduced in 1966 by D. Ginsbu ...
s.
Compounds
The best known paddlane is
.1.1.1addlane which can be seen as a precursor to
octahedrane (C
6), an allotrope of elemental carbon.
The American chemist
Philip Eaton
Philip E. Eaton (born 1936) is a Professor Emeritus of Chemistry at the University of Chicago. He and his fellow researchers were the first to synthesize the "impossible" cubane molecule in 1964.P. Eaton and T. W. Cole, The Cubane System, J. Am. ...
, famous for being the first to synthesize the "impossible"
cubane
Cubane () is a synthetic hydrocarbon compound that consists of eight carbon atoms arranged at the corners of a cube, with one hydrogen atom attached to each carbon atom. A solid crystalline substance, cubane is one of the Platonic hydrocarbons an ...
molecule, has conducted studies for the synthesis of
.2.2.2addlane.
The first mention of paddlane goes back to 1973.
References
See also
*
Propellane
In organic chemistry, propellane is any member of a class of polycyclic hydrocarbons, whose carbon skeleton consists of three rings of carbon atoms sharing a common carbon–carbon covalent bond. The concept was introduced in 1966 by D. Ginsbu ...
*
Fenestrane
A fenestrane in organic chemistry is a type of chemical compound with a central quaternary carbon atom which serves as a common vertex for four fused carbocycles. They can be regarded as spiro compounds twice over. Because of their inherent st ...
*
Inverted tetrahedral geometry
In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are cos−1(−) = 109.4712206...° ≈ 109.5° when all four substituents are ...
Hydrocarbons
Tricyclic compounds
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