A staffane or [n]staffane is an organic compound, a polycyclic hydrocarbon with molecular structure H-[-C≡(-CH2-)3≡C-]n-H, for some integer n ≥ 1.
The chemical formula is therefore C5nH6n+2 Staffanes were first obtained in 1988 by Piotr Kaszyński[1][2][3] and Josef Michl, by spontaneous polymerization of [1.1.1]-propellane C5H6 or C2(=CH2)3.
[4] In the reaction, the axial C-C bond of the propellane (the "bridge") is broken, creating a free bond on each of the two axial carbons (the "bridgeheads").
The resulting structural unit [-C≡(-CH2-)3≡C-] is a rigid cage, consisting of two carbon atoms joined by three methylene bridges; therefore the joined units are constrained to lie on a straight line.
This feature has generated substantial interest among nanotechnology researchers, who have considered staffane oligomers as convenient "rigid rods" for building all sorts of nanostructures.