Staffane

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 C_5nH_6n+2

Staffanes were first obtained in 1988 by P. Kazynski and J. Michl, by spontaneous polymerization of [1.1.1]-propellane C₅H₆ or C₂(=CH₂)₃.^[1] 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 ribs; therefore the joined units are constrained to lie on 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.^[1]

An oligomer with a specific number n of units is denoted by [n]staffane (e.g., [1]staffane, [2]staffane, etc..) The notation [n]staffane is used when the number of units is variable or unspecified; in this case the "n" in the brackets is not a variable, but the letter "n", considered part of the name.

References

1. ^ ^{a b} P. Kazynsky, J.Michl (1988), [n]Staffanes: a molecular-size Tinkertoy construction set for nanotechnology. Preparation of end-functionalized telomers and a polymer of [1.1.1]propellane. Journal of the American Chemical Society, volume 110, issue 15, pp. 5225–5226