Distance between arrow and reaction product

Question

Please tell me, How I can reduce a distance between arrow and feed substances. I want the same distances at all three directions. To make it clearer, I explain: I drew the side substances as a massive elements in order to the scheme acquired roundness. To get a nice scheme. In my opinion each of the array elements has a rectangular invisible borders which can not overlap with an arrows, so the lower elements have lager distances between arrows than the upper. How to solve this problem? Thanks in advance

enter image description here

\documentclass{article} 
\usepackage{chemfig}
\usepackage{tikz}

\begin{document}

\begin{figure}[!h]
\begin{center}
\setchemrel{}{}{3em}
\noindent
\schemestart
\chemfig{%
**6(------)
}
\arrow{<=>}[90]
\chemfig{%
*6(---
    ([,,,,draw=none]-([,,,,draw=black]*6(--
        ([,,,,draw=none]-([:-18,,,,draw=black]*5(----(-)-)))
    ----)))
-(-)--)
}
\arrow(@c1--){<=>}[210]
\chemfig{%
**6(-
    ([,,,,draw=none]-([,,,,draw=black]**6(-(-)---
        ([,,,,draw=none]-([,,,,draw=black]**6(-(-)--(-)---)))
    --)))
----*6(--)-)
}
\arrow(@c1--){<=>}[330]
\chemfig{%
-[:30]-[:-30]-[:30](-[:90])-[:-30]
-[:-90,,,,draw=none]-[:210,,,,draw=black]-[:150]-[:210]-[:150]-[:210]
-[:-90,,,,draw=none](-[:210]-[:150])-[:-30,,,,draw=black]-[:30]-[:-30]-[:30]
}
\schemestop
\caption{Reforming} \label{fig:Precursors}
\end{center}
\end{figure}

\end{document}

A small, unrelated tip: use \centering instead of \begin{center} in a figure. Welcome to TeX.SX! — darthbith, Sep 08 '14 at 20:00

cgnieder · Accepted Answer · 2014-09-08T21:06:05.267

The “problem” is empty space. The arrows actually are not far away from what chemfig sees as compound. You can verify this by adding \schemedebug{true}:

\documentclass{article} 
\usepackage{chemfig}
\usepackage{tikz}

\begin{document}

\begin{figure}
  \centering
  \schemedebug{true}
  \setatomsep{1.5em}
  \schemestart
    \chemfig{**6(------)}
    \arrow{<=>}[90]
    \subscheme{
      \chemfig{*6(----(-)--)}
      \arrow{0}[20,.3]
      \chemfig{*6(------)}
      \arrow{0}[-30,.2]
      \chemfig{*5(---(-)--)}
    }
    \arrow(@c1--){<=>}[210]
    \null
    \subscheme{
      \chemfig{-[:30]**6(--(-)----)}
      \arrow{0}[-90,.3]
      \chemfig{-[:30]-[:-30]**6(------)}
      \arrow{0}[-40,.1]
      \chemfig{-[:-30]**6(------)}
    }
    \arrow(@c1--){<=>}[330]
    \subscheme{
      \chemfig{-[:30]-[:-30]-[:30]-[:-30]-[:30]}
      \arrow{0}[-120,.1]
      \chemfig{-[:30]-[:-30]-[:30](-[:90])-[:-30]}
      \arrow{0}[-130,.4]
      \chemfig{-[:-30]-[:30]-[:-30]-[:30]-[:-30]-[:30]}
    }
  \schemestop
  \caption{Reforming} \label{fig:Precursors}
\end{figure}

\end{document}

enter image description here

A possible idea (which uses the subschemes that I used for the clusters of molecules with single \chemfig's for each molecule): connect the center and the surroundings with shortened invisible arrows and latter connect the center with specific molecules in the clusters. (I also scaled all molecules by using e reduced atom-sep (\setatomsep{1.5em}).)

\documentclass{article} 
\usepackage{chemfig}
\usepackage{tikz}

\begin{document}

\begin{figure}
  \centering
  \schemedebug{true}
  \setatomsep{1.5em}
  \schemestart
    \chemfig{**6(------)}
    \arrow{<=>}[90]
    \subscheme{
      \chemfig{*6(----(-)--)}
      \arrow{0}[20,.3]
      \chemfig{*6(------)}
      \arrow{0}[-30,.2]
      \chemfig{*5(---(-)--)}
    }
    \arrow(@c1--){0}[210,.1]% invisible
    \subscheme{
      \chemfig{-[:30]**6(--(-)----)}
      \arrow{0}[-90,.3]
      \chemfig{-[:30]-[:-30]**6(------)}
      \arrow{0}[-40,.1]
      \chemfig{-[:-30]**6(------)}
    }
    \arrow(@c1--){0}[330,.1]% invisible
    \subscheme{
      \chemfig{-[:30]-[:-30]-[:30]-[:-30]-[:30]}
      \arrow{0}[-120,.1]
      \chemfig{-[:30]-[:-30]-[:30](-[:90])-[:-30]}
      \arrow{0}[-130,.4]
      \chemfig{-[:-30]-[:30]-[:-30]-[:30]-[:-30]-[:30]}
    }
    % connect with arrows:
    \arrow(@c1--@c8){<=>}
    \arrow(@c1--@c12){<=>}
  \schemestop
  \caption{Reforming} \label{fig:Precursors}
\end{figure}

\end{document}

enter image description here

Yes, in this case the substances are closer to the arrows. But I drew the side substances as a massive elements in order to the scheme acquired roundness. To get a nice scheme. In my opinion each of the array elements can not overlap with an arrow, so the lower elements have lager distances between arrows than the upper. — EvgenyChem, Sep 08 '14 at 20:25
You should have mentioned that requirement in your question. I'll revise my answer in a bit... — cgnieder, Sep 08 '14 at 20:26
And of course I do not know how to make the scheme a little less. It goes abroad. This is another problem. — EvgenyChem, Sep 08 '14 at 20:31
Great, thank you. This is much better. Now I will understand. — EvgenyChem, Sep 08 '14 at 21:16

Distance between arrow and reaction product

1 Answers1