# Chemfig, TikZ, circle diagram

I have a problem with drawing such a complex diagram in using Chemfig (a picture of diagram should be attached) . The Chemfig manual describes how to draw curved and U-type arrows but all my attempts to combine both of them into desired diagram failed. If someone comes up with an idea how to do that I'll be very grateful.

Thank you.

• What do you have so far? – soandos May 9 '13 at 4:52
• This is not easily done with chemfig alone, I believe. You either need to use TikZ directly for coding the arrows or think of another way to display the information of the scheme. – cgnieder May 9 '13 at 9:45

chemfig does not provide curved arrows. It is possible to define something with \definearrow - the documentation gives an example. This is not comfortable to use and is only part of what your scheme has: combined curved arrows.

It is probably possible to define such arrows, too, but I don't believe that they're any more comfortable to use. I would try to avoid them completely and instead use what is available already.

\documentclass{article}
\usepackage{chemfig}
\usepackage{chemmacros}
\chemsetup[ox]{pos=super}
\DeclareChemIUPAC\tBu{\textsuperscript{\textit{t}}Bu}

% \usepackage{showframe}

\begin{document}

\begin{center}
\small
\schemestart[,2]
\chemfig{R_2-\ox{2,Pd}-R_1}
\arrow(start--)[45]
\ox{0,Pd}
\arrow(--X){->[*{0.180} $+$ \chemfig{R_2-X}]}[-45]
\chemfig{R_2-\ox{2,Pd}-X}
\arrow(--tBu){->[*{0.0} $+$ NaO\tBu][*{0.180} $-$ NaX]}[-135]
\chemfig{R_2-\ox{2,Pd}-O\tBu}
\arrow(@tBu--@start){->}
%%
% remember this point, \mbox to actually create an empty node
\arrow(@tBu--rem1){0}[135,1] \mbox{}
\arrow(@rem1--)[180]
\chemfig{
(-[2]OH)(-[6]OH)(-[3,,,,draw=none]Na^{\fplus})
-O\tBu
}
\arrow(@rem1--){<-}[-120,1.25]
\chemfig{
(-[2]OH)(-[6]OH)(-[3,,,,draw=none]Na^{\fplus})
-O\tBu
}
\arrow{<-}[180,1]
\chemfig{R_1-B(-[:-60]OH)-[:60]OH}
%%
% remember this point, \mbox to actually create an empty node
\arrow(@start--rem2){0}[45,1] \mbox{}
\arrow(@rem2--)[135,1]
\chemfig{R_1-R_2}
\schemestop
\end{center}

\end{document}

• That's a whole bunch of arrows my friend! – azetina May 9 '13 at 17:13
• @azetina true. I don't really like the scheme as it is. There surely is a better way to present the whole thing... – cgnieder May 9 '13 at 17:42