# Vertical alignment of molecules

\begin{scheme}[h]
\centering
%\setcrambond{3pt}{1pt}{1pt}
%\setbondoffset{3pt}
\scriptsize\chemfig{(-[::60]R_1)(=[::180]O)-[::-60]O-[::-60]-[::60](-[::60]O-[::-60](-     [::60]R_2)(=[::-60]O))-[::-60]-[::60]O-[::-60](=[::60]O)(-[::-60]R_3)} + H_2O
\chemrel{<->}
\scriptsize\chemfig{(-[::60]R_1)(=[::180]O)-[::-60]O}
\chemsign{+}
\scriptsize\chemfig{(-[::60]R_1)(=[::180]O)-[::-60]O}
\chemsign{+}
\scriptsize\chemfig{(-[::60]R_1)(=[::180]O)-[::-60]O}
\chemsign{+}
\scriptsize\chemfig{(-[::60]R_1)(=[::180]O)-[::-60]O}
\caption{reaction}
\label{sn:reaction}
\end{scheme}


How can I achieve that vertical alignment? I looked through the manual however there seemed no special command to mark the branch or molecule which everything else should align at. Also, why is the O italic?

I saw a solution with invisible arrows but it seems like it doesn't work here. \arrow{0}[,0] will result in [,0] being written before my equation.

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I'm not familiar with chemfig, but I would bet that the _ is setting off math-mode for the following text—thus the O is italicized. I don't think chemfig is meant to handle the standard notation in this way; I would look for an alternative in the manual (or maybe you can use \ch from mhchemmaybe). –  Sean Allred Jan 22 '14 at 18:37
Thank you! \ch or \text should do! –  idkfa Jan 22 '14 at 19:53

I don't how how if this is the right way, to mark my questions as answered. however I found the solutionen. As mentionend above I already came across \arrow{0}[,0] the trick. I had to use:

\begin{scheme}
\schemestart
[...]
\schemestop
\end{scheme}


Original Question: here

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