Why does this chemfig bond with a hook start in the middle of the atom?

Question

I've been using the chemfig package to typeset my chemistry notes, and when trying to make an arene something went wrong:

Naturally, I'd like it to not start from the middle of the atom. The chemfig documentation has an example similar to this:

That example works fine for me too. Yet for some reason, my very similar attempt seems to start too early. How could I fix this?

My code:

\documentclass{article}
\usepackage{chemfig}
\begin{document}

\chemfig{
C?[firstC](-[::-30]R) %right lower carbon
-[:90]C(-[::-60]R) %right upper
=[::60]C(-[::-60]R) %top
-[::60]C(-[::-60]R) %left upper 
=[::60]C(-[::-60]R) %left lower
-[::60]C(?[firstC,2])(-[::-60]R)} %bottom 

\end{document}

Answer 1

Your second hook is inside of a branch. Just remove the parentheses from the hook, C?[firstC,2] instead of C?([firstC,2]). Below I also propose a second version of the molecule using chemfig's ring syntax.

\documentclass{article}
\usepackage{chemfig}
\begin{document}

\chemfig{
  C?[firstC](-[::-30]R) %right lower carbon
  -[:90]C(-[::-60]R) % right upper
  =[::60]C(-[::-60]R) % top
  -[::60]C(-[::-60]R) % left upper 
  =[::60]C(-[::-60]R) % left lower
  -[::60]C?[firstC,2](-[::-60]R)
} %bottom 

\bigskip or alternatively:

\chemfig{C*6((-R)-C(-R)=C(-R)-C(-R)=C(-R)-C(-R)=)}

\end{document}