Badly drawn bonds


One thing that really irritates me is badly drawn ChemDraw structures (maybe I should get out more…).

Anyway, there is no excuse for a benzene ring not being a perfect hexagon – unless of course you’re showing perspective or drawing a fullerene or nanotube. Double and triple bonds should be well separated so that they don’t just look like thick bonds. And as for angles… unless there’s a really good reason for it not to be 120 or 180 degrees (depending on the hybridisation flavour of your [carbon] atoms), then there is likely something wrong; in flatland, even your sp3 centres should be 120 degrees unless you’re showing the stereochemistry and need to draw all four bonds. Atom labels should be in a consistent font (preferably Helvetica) and should be of a size that does not require one to use some kind of electron microscope to read them.

Simple really… so why do a lot of ChemDraw structures that appear in papers or on slides at conferences look like a six-year old has drawn them with a crayon (and I mean a particularly untalented six-year old at that – one that probably wouldn’t even win a Blue Peter drawing competition)? I think it’s just people being lazy…

I’ve been to a couple of conferences in the last month and gasped in horror (that may be a slight exaggeration) at some of the representations of C60 I’ve seen. Somewhat annoying is when the double bonds are drawn inside the pentagonal rings – please, can everyone just agree from now on to put them in the six-membered rings (surely it makes more sense that way?) . When I confronted one speaker about the ChemDraw crimes they had perpetrated, I was told that they’d just used the template… – and yes, it turns out that some of the C60 structures in the template library have dubious patterns of bonding…

Even worse, I see the occasional 5- and 6-bonded carbon atoms in fullerenes (and pyrene seems to fall into that trap as well). Maybe it shouldn’t get under my skin as much as it does, but this is how organic chemists communicate – and wrong is wrong. You wouldn’t use ‘2’ in an equation if it called for the square root of 2, so let’s be a bit more careful about our structures.

Right, soap-box carefully stowed away now for another day…


Stuart Cantrill (Associate Editor, Nature Nanotechnology)

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