In
organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...
, paddlane is any member of a class of
tricyclic
Tricyclics are cyclic chemical compounds that contain three fused rings of atoms.
Many compounds have a tricyclic structure, but in pharmacology, the term has traditionally been reserved to describe heterocyclic drugs. They include antidepr ...
saturated hydrocarbon
In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in whi ...
s having two bridgehead carbon atoms joined by four
bridge
A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...
s. The name derives from a supposed resemblance of the molecule to a
paddle wheel
A paddle is a handheld tool with an elongated handle and a flat, widened end (the ''blade'') used as a lever to apply force onto the bladed end. It most commonly describes a completely handheld tool used to propel a human-powered watercraft by p ...
: 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 compound, polycyclic hydrocarbons, whose carbon skeleton consists of three rings of carbon atoms sharing a common carbon–carbon bond, carbon–carbon covalent bond. The co ...
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 (June 2, 1936 – July 21, 2023) was an American chemist. He served as Professor Emeritus of Chemistry at the University of Chicago. Eaton and his fellow researchers were the first to synthesize the "impossible" cubane molecule in ...
, famous for being the first to synthesize the "impossible"
cubane
Cubane is a synthetic hydrocarbon compound with the Chemical formula, formula . It consists of eight carbon atoms arranged at the corners of a Cube (geometry), cube, with one hydrogen atom attached to each carbon atom. A solid crystalline substanc ...
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 compound, polycyclic hydrocarbons, whose carbon skeleton consists of three rings of carbon atoms sharing a common carbon–carbon bond, carbon–carbon covalent bond. The co ...
*
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 arccos(−) = 109.4712206...° ≈ 109.5° when all four substituents are ...
Hydrocarbons
Tricyclic compounds
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