# chemfig, how to do these wavy markings?

I am trying to reproduce this:

So far I have:

\documentclass{memoir}
\usepackage{tikz}
\usepackage{chemfig}
\usetikzlibrary{decorations.pathmorphing}
\begin{document}

\chemfig{*5(5-1-2(-((-[:90,1,,,decorate,decoration=snake])-[:-90,1,,,decorate,decoration=snake]))-3-4*6(-6-7-8-9-5-)-)}

\end{document}


But the wavy line really doesn't look very good. Can someone think of a better way of doing that? Also, looking at the number 5 there is something strange going on there. What's wrong with that?

You might want to use the decoration complete sines from Nicer wavy line with TikZ as I've used in a blog post of mine a while ago:

\documentclass{article}
\usepackage{tikz}
\usepackage{chemfig}
\usetikzlibrary{decorations.pathmorphing}

\pgfdeclaredecoration{complete sines}{initial}{
\state{initial}[
width=+0pt,
next state=sine,
persistent precomputation={
\pgfmathsetmacro\matchinglength{
\pgfdecoratedinputsegmentlength /
int(\pgfdecoratedinputsegmentlength/\pgfdecorationsegmentlength)
}
\setlength{\pgfdecorationsegmentlength}{\matchinglength pt}
}]{}
\state{sine}[width=\pgfdecorationsegmentlength]{
\pgfpathsine{
\pgfpoint
{0.25\pgfdecorationsegmentlength}
{0.5\pgfdecorationsegmentamplitude}
}
\pgfpathcosine{
\pgfpoint
{0.25\pgfdecorationsegmentlength}
{-0.5\pgfdecorationsegmentamplitude}
}
\pgfpathsine{
\pgfpoint
{0.25\pgfdecorationsegmentlength}
{-0.5\pgfdecorationsegmentamplitude}
}
\pgfpathcosine{
\pgfpoint
{0.25\pgfdecorationsegmentlength}
{0.5\pgfdecorationsegmentamplitude}
}
}
\state{final}{}
}

\tikzset{wv/.style={decorate,decoration=complete sines}}

\begin{document}

\chemfig{*5(5-1-2(-((-[:90,1,,,wv])-[:-90,1,,,wv]))-3-4*6(-6-7-8-9-5-))}

\end{document}


For reproducing the picture I'd probably also define a submol:

\tikzset{wv/.style={decorate,decoration=complete sines}}
\definesubmol{R}{-[,.5]((-[::90,.5,,,wv])-[::-90,.5,,,wv])}


and then:

\chemfig{*5(9-1-2(!R)-3(!R)-4*6(-5-6-7-8-9-))}


For more customization of the wavy bond you might be interested in this blog post by Joseph Wright: Exploring ChemFig: Going further