Chemistry Blog



Dec 09

Neat-o Curved Arrows in Chemdraw

by azmanam | Categories: chem 2.0, chemical education, fun, opinion, synthetic chemistry | (44682 Views)

UPDATE: New Catalytic Cycle video below!

James (of Master Organic Chemistry and the Reagents App/Guide fame) and I had some off-line conversations about curved arrows in ChemDraw. I don’t particularly like the suite of arrows ChemDraw gives us in the Arrow Tools menu. Yeah, they give you 4 arc angles, but you have to guess if you need the clockwise or counterclockwise arrow… and I just don’t like them. They look, i dunno, amateur or less professional or something.  Nothing against people who use the standard arrows, I just don’t like them.

So over the years I’ve become quite adept at using the Edit Curve function in ChemDraw.  It allows me to make my arrows look however I want them to.  I have a couple of arrow shapes I particularly enjoy, and I use them a lot.

James (@jamesashchem) gave me a hat tip on Twitter for showing him the new arrows, at which point Mark Peczuh (@mwpeczuh) requested a public YouTube video.

So I made one.  Here it is.  If you already know how to use the Edit Curve function then cool.  If not, hope it helps :)


Thanks to everyone who left kind comments about the curved arrow video.  Stephen Davey (@stephengdavey) asked if the Edit Curve function could make curly q arrows.  I’d never tried to make one like that before, so I took a crack at it.  Turns out, this arrow doesn’t work so well with the Edit Curve function (unless some actual graphic designer knows more about making paths than I do.  If so, please let me know!!).  I ended up combining an arc, an arrow, and a circle and the effect looked ok.  Here are my failed attempts, plus the final output (click for larger):

Later, Bal (@gnak_lab) asked about an easy way to draw catalytic cycles.  I think the question was referring to the “circle of arrows” like in this mechanism for the Heck reaction.  I’ve done catalytic cycles before, but was never really pleased with the result either.  Then I had an idea.  You can add curvature to straight arrows… so I though if I started with a circle as a template, added the arrows, then deleted the circle, that might just work.  So without practicing first, I shot a video on me making the catalytic cycle for the Sonogashira reaction (I just recreated the mechanism from that site).  The video for that is below.  It’s not a polished mechanism, I’d go back and tweak a few things, but for a first try, I think it turned out pretty well :)

(video at 2x speed for brevity)


1 ping

Skip to comment form

  1. azmanam

    If you’re doing the catalytic cycle this way, you may want to turn off Fixed Angles (in Object menu). You might notice I have some problems with the fixed angles in my example. Turning them off will fix that problem.

  2. James

    To draw the nice catalytic cycle arrows, I did exactly what you described: drew a circle in Chem Draw, drew a straight arrow and then adjusted the curve of the arrow to match the arc of the circle. Was happy with the result.
    Thanks for doing this, we can all use some help with our Chemdraw-fu

  3. Scott

    Curved. Swords.

  4. Suzie

    Another way to solve the problem of having nice catalytic cycles is to draw a circle, position the molecules on top and then import into CS illustrator, clip out the extra parts of the circle and add arrow heads. I find this strategy to be much easier and fairly quick.

  1. Drawing Chemicals « Organic Chemistry Tips and Techniques

    […] As azmanam relates, the edit curve tool makes everything oh so pretty.  This post comes complete with its own youtube video as well, for visual learners.  Colorblind Chemistry also covered this topic recently, in the context of catalytic cycles. […]

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Powered by sweet Captcha