Chemistry

A chemfig package is based on tikz package. It is used to draw chemical structure diagrams. The manual of this package can be found in your $\TeX$ system. You may want to try the following examples:

1. Triphenylmethane

\documentclass{article} \usepackage{chemfig} % draw chemical figure \usepackage{float} % determine figure position \begin{document} This is an example of drawing Triphenylmethane! \begin{figure}[H] \centering % first method \chemfig{*6(-=-*6(-(-*6(=-=-=-))-*6(=-=-=-))=-=)} % second method \definesubmol{@}{*6(=-=-=-)} \chemfig{(-[:-30]!@)(-[:90]!@)(-[:210]!@)} \caption{Triphenylmethane} \end{figure} For more detail, the reader may refer to the chemfig package manual. \end{document}

2. Caffeine

\documentclass{article} \usepackage{chemfig} % draw chemical figure \usepackage{float} % determine figure position \begin{document} This is an example of drawing Caffeine! \begin{figure}[H] \centering \chemfig{*6((=O)-N(-CH_3)-*5(-N=-N(-CH_3)-=)--(=O)-N(-H_3C)-)} \caption{Caffeine} \end{figure} For more detail, the reader may refer to the chemfig package manual. \end{document}

3. Chemical Reaction

\documentclass{article} \usepackage{chemfig} % draw chemical figure \usepackage{float} % determine figure position \begin{document} This is an example of drawing Chemical reaction! \begin{figure}[H] \centering \chemname{\chemfig{R-C(-[:-30]OH)=[:30]O}}{Carboxylic acid} \chemsign{+} \chemname{\chemfig{R'OH}}{Alcohol} \chemrel{->} \chemname{\chemfig{R-C(-[:-30]OR')=[:30]O}}{Ester} \chemsign{+} \chemname{\chemfig{H_2O}}{Water} \chemnameinit{} \caption{Reaction} \end{figure} For more detail, the reader may refer to the chemfig package manual. \end{document}

You may also have a look at other packages used for drawing molecules like ochem, streetex and xymtex.

The mhchem package provides commands for typesetting chemical molecular formulas and equations. To use this package, we can find its manual in our installed $\TeX$ distribution. See the following samples:

\documentclass{article} \usepackage{chemfig} % draw chemical figure \usepackage{float} % determine figure position \begin{document} This is an example of drawing Chemical reaction! \begin{figure}[H] \centering \setatomsep{2.5em} \setcompoundsep{5em} \schemestart \chemfig{R-@{aton}\lewis{2,N}H_2} \+ \chemfig{@{atoc}C([3]-CH_3)([5]-CH_3)=[@{atoo1}]O} \chemfig{@{atoo2}\chemabove{H}{\scriptstyle\oplus}} \chemmove[-stealth,shorten <=3pt,dash pattern= on 1pt off 1pt,thin]{ \draw[shorten >=2pt](aton) ..controls +(up:10mm) and +(left:5mm)..(atoc); \draw[shorten >=8pt](atoo1) ..controls +(up:10mm) and +(north west:10mm)..(atoo2);} \arrow{<=>[\tiny addition]} \chemfig{R-@{aton}\chembelow{N}{\scriptstyle\oplus}H([2]-[@{sb}]H)-C(-[2]CH_3)(-[6]CH_3)-OH} \schemestop \chemmove{ \draw[-stealth,dash pattern= on 1pt off 1pt,shorten <=3pt, shorten >=2pt] (sb)..controls +(left:5mm) and +(135:2mm)..(aton);} \par \schemestart \arrow{<=>} \chemfig{R-@{aton}\lewis{2,N}([6]-[@{sbh}]H)-[@{sb}]C(-[2]CH_3)(-[6]CH_3)-[@{sbo}]@{atoo} \chemabove{O}{\scriptstyle\oplus}(-[1]H)(-[7]H)} \chemmove[-stealth,shorten <=3pt,shorten >=2pt,dash pattern= on 1pt off 1pt,thin]{ \draw(aton) ..controls +(up:5mm) and +(up:5mm)..(sb); \draw(sbh) ..controls +(left:5mm) and +(south west:5mm)..(aton); \draw(sbo) ..controls +(up:5mm) and +(north west:5mm)..(atoo);} \arrow{<=>[\tiny élimination]}\chemfig{R-N=C(-[1]CH_3)(-[7]CH_3)} \+ \chemfig{H_3\chemabove{O}{\scriptstyle\oplus}} \schemestop \caption{Reaction} \end{figure} For more detail, the reader may refer to the chemfig package manual. \end{document}

Other packages provide commands and macros for typesetting chemical formulas are chemformula and chemmacros.