# Electron movement between compounds in reaction schemes

I tried to draw some reaction schemes with some electron movements using the chemfig macros.

Problem is: I can draw every electron movement but in schemes only inside a certain compound of the reaction. If the nodes for the drawn arrow are in different compounds the arrow appears anywhere else but where I want it to. Same happens if the \chemmove-order is posted after a compound-differing arrow. Meaning it looks like the nodes get somehow "spoiled" once there is an arrow slicing compounds between the nodes and the \chemmove part.

Here are some examples.

This works:

\documentclass{article}

\usepackage{chemfig}
\usetikzlibrary{decorations}

\usepackage{chemmacros}
\begin{document}
\schemestart
\setchemrel{}{}{8em}
\chemfig{R-[:30](-[:-30,.25,,,draw=none]@{fp}\fplus)=^[:90]O}
\chemrel[\chemfig{*6(-=-=-=[@{b}])}][]{<>}
\schemestop
\chemmove{
\draw[->,red,shorten >=3pt, shorten <=3pt]
(b) .. controls +(-120:8mm) and +(-90:8mm) .. (fp) ;
}


But this doesn't:

\documentclass{article}

\usepackage{chemfig}
\usetikzlibrary{decorations}

\usepackage{chemmacros}
\begin{document}
\schemestart
\chemfig{R-[:30](-[:-30,.25,,,draw=none]@{fp}\fplus)=^[:90]O}
\arrow{<=>[*{0}\chemfig{*6(-=-=-=[@{b}])}]}[,1.5]
\schemestop
\chemmove{
\draw[->,red,shorten >=3pt, shorten <=3pt]
(b) .. controls +(-120:8mm) and +(-90:8mm) .. (fp) ;
}
\end{document}


I tried to work around it by using \chemrel instead of \arrow but this makes alignments horrible.

• Try placing \chemmove after \schemestop. mychemistry is rather unmaintained but if you notice something not working you could tell the author, anyway – cgnieder Oct 28 '14 at 9:34
• Tried it, same results. Thx for the editing btw, I'm a newbie here. – Zajonik Oct 28 '14 at 9:44
• In this case we're going to need a complete and compilable example (a MWE) with which we can reproduce the behaviour. In principle \chemmove and \arrow can be combined (see texwelt.de/wissen/fragen/5734#5738 for an example...) – cgnieder Oct 28 '14 at 10:07
• My header is rather big as I am writing my PhD with it but I do get similar results with the example you sent in the comment, so I will edit the question with a different (easier), complete and compilable example which should have the same problem. I am using TexNic Center 1.0 Stable Release Candidate 1 with a LaTex=>PS=>PDF Compilation – Zajonik Oct 28 '14 at 12:34
• We don't need your complete header. \usepackage{chemfig} should suffice. What we need is to be able to reproduce your problem. – cgnieder Oct 28 '14 at 12:37

This problem appears when you use a compilation over PS to PDF. If you want to make reaction schemes using \usepackage{chemfig} you should compile with pdflatex (LaTex=>PDF).

Another solution (not very nice) would be to manually adjust all the offsets. This should work also if compiled over PS to PDF:

\documentclass{article}

\usepackage{chemmacros}
\usepackage{chemfig}
\usetikzlibrary{decorations}

\begin{document}

\schemestart
\chemfig{R-[:30](-[:-30,.25,,,draw=none]@{fp}\fplus)=^[:90]O}
\arrow(.340--){<=>[*{0}\chemfig{*6(-=-=-=[@{b}])}]}[,1.5]
\schemestop
\chemmove[->,red,shorten <=3pt,shorten >=3pt]{
\draw([yshift=40pt,xshift=20pt]fp.190)..controls+(-95:8mm)and+(-90:8mm)..([yshift=-4pt,xshift=35pt]b);}

\end{document}