# How to draw an arenium ion with chemfig?

This question is fairly straightforward, I hope. I want to achieve this, including the plus and the incomplete circle.

I can already draw the benzene bit with chemfig, positioning the plus and removing the part of the electron delocalisation circle is what I'm looking for.

It looks like a lot of places draw it by placing an \oplus on the carbon at the top, but I can't do that for my output.

Thanks.

Here's an idea:

\documentclass{article}
\usepackage{chemfig}

\begin{document}

\chemfig{**[60,-240]6(-(-[:90,,,,draw=none]+)---(-[:60]R)(-[:120]H)--)}

\end{document}


Have a look at section Rings > Angular Position for the arc inside the ring and section Customization of bonds (for draw=none) of chemfig's manual.

• Nice. If I may suggest: I'd do the diagonal edges shorter (not sure how) and with a wider angle, maybe (-[:45]R)(-[:135]H)? Jan 27 '16 at 14:52
• @Alenanno bonds have five parameters: <bond>[<angle>,<factor>,<arrival>,<departure>,<tikz code>]. Those changes are up to you :) They aren't the essential patr of the question. Jan 27 '16 at 15:36
• Why up to me? It's not my question. :) Jan 27 '16 at 15:52
• @Alenanno I meant if you ever need to draw this kind of ion in one of your documents you're (of course) free to change the molecule details such as bond lengths :) Jan 27 '16 at 16:09
• Mine was simply a suggestion for this particular answer. You're free to accept the suggestion or not, but I don't see the relevance of what you're saying. Jan 27 '16 at 16:17