title: Paddlane
text: # Paddlane
  
  In organic chemistry, paddlane is any member of a class of tricyclic saturated hydrocarbons having two bridgehead carbon atoms joined by four bridges. The name derives from a supposed resemblance of the molecule to a paddle wheel: namely, the rings would be the propeller's blades, and the shared carbon atoms would be its axis.
  
  Systematically named tricyclo $[m.n.o.p^{1,m+2}]alkanes,$ these compounds have been referred to as [m.n.o.p]paddlanes. The notation [m.n.o.p]paddlane 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 propellanes.
  
  ## Compounds
  
  The best known paddlane is [1.1.1.1]paddlane which can be seen as a precursor to octahedrane $(C_6),$ an allotrope of elemental carbon.
  
  The American chemist Philip Eaton, famous for being the first to synthesize the "impossible" cubane molecule, has conducted studies for the synthesis of [2.2.2.2]paddlane. The first mention of paddlane goes back to 1973.
  
  