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Helicene (mmm, twisty)

By moleculeoftheday on January 29, 2008.

After this weekend's discussion of chirality in advertising, I figured I'd post an interesting, more rigorous example of chirality. Most chiral (left- or right-handed)molecules have "asymmetric" carbons, or ones with all different things attached.

i-48e03299368c0729626746ad06ff63cc-helicene.png

Helicene, by contrast, has none. However, it's got a twist that imparts chirality to it. Think of a left- and right-handed staircase. This, in itself, constitutes chirality - for example, DNA (almost always) twists right. If you put left-handed DNA in ads for your biotechnology company, scientists will make fun of you.

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Topologically/Geometrically Interesting

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www.drugsandpoisons.com/

where there is an interesting post on the chirality of penicillamine, a metabolite of penicillin that is used as a chelating agent. The L-isomer is apparently toxic.