Brauche Hilfe mit dem Paket "Chemfig"

\documentclass{scrartcl}

\DeclareNewTOC[
  type=scheme,
  types=schemes,% used in the \listof.. command
  float,
  name=Schema,
  listname={Verzeichnis der Schemata}
]{los}

\usepackage{chemfig}
\usetikzlibrary{decorations}% chemfig lädt TikZ

% eine delokalisierte Doppelbindung
\makeatletter
\pgfdeclaredecoration{ddbond}{initial}{
  \state{initial}[width=2pt]{
    \pgfpathlineto{\pgfpoint{2pt}{0pt}}
    \pgfpathmoveto{\pgfpoint{1pt}{\CF@double@sep}}
    \pgfpathlineto{\pgfpoint{1.5pt}{\CF@double@sep}}
    \pgfpathmoveto{\pgfpoint{2pt}{0pt}}
  }
  \state{final}{\pgfpathlineto{\pgfpointdecoratedpathlast}}
}
\makeatother
\tikzset{
  lddbond/.style={decorate,decoration=ddbond},
  rddbond/.style={decorate,decoration={ddbond,mirror}},
  elmove/.style={->,red,shorten >=3pt, shorten <=3pt}
}

\setatomsep{1.78500 em}
\setbondstyle{line width = 0.06642 em}
\renewcommand*\printatom[1]{\ensuremath{\mathsf{#1}}}

\usepackage{chemmacros}% für formale Ladungen
\chemsetup{
  chemformula/format = \sffamily
}

\usepackage{chemnum}

\begin{document}

\begin{scheme}
  \small\centering
  \setcompoundsep{6.5em}
  \setchemnum{format=\bfseries\sffamily}
  \schemestart
    \chemname{\chemfig{R-[:30](=[:90]O)-[:-30]Cl}}{\cmpd{chlorid}}
    \arrow(.base east--.base west){<=>[\ch{+ AlCl3}][][20pt]}
    \chemname{%
      \chemfig{
        R-[:30](
          -[:90,,,,rddbond]O
          -[:45,,,,dotted]\chemabove{Al}{\fdelm}Cl_3
        )(-[:160,.4,,,draw=none]\fdelp)
        -[:-30]Cl
      }%
    }{\cmpd{chlorid-AlCl3-A}}
    \arrow(.base east--.base west){<=>[][][20pt]}
    \chemname[4ex]{%
      \chemfig{
        R-[:30](
          =[:90]O
        )
        (-[:160,.4,,,draw=none]\fdelp)
        -[@{b}:-30,,,,dotted]@{Cl}Cl
        -[:30,,,,dotted]\chemabove{Al}{\fdelm}Cl_3
      }%
    }{\cmpd{chlorid-AlCl3-B}}
    \chemmove{
      \draw[elmove]
        (b) .. controls +(-120:8mm) and +(-90:8mm) .. (Cl) ;
    }
    \arrow(.base east--.base west){<=>[][{\ch[circled]{- AlCl4-}}][20pt]}
    \chemname
      {\chemfig{R-[:30](-[:-30,.25,,,draw=none]@{fp}\fplus)=^[:90]O}}
      {\cmpd{carbonyl-kation}}
    \arrow{<=>[*{0}\chemname{\chemfig{*6(-=-=[@{b}]-=)}}{\cmpd{benzol}}]}[-90]
    \chemmove{
      \draw[elmove]
        (b) .. controls +(60:8mm) and +(-90:8mm) .. (fp) ;
    }
    \chemname{%
      \chemfig{
        R-[:30](=[:90]O)-[:-30](-[@{b1}:90]@{H}H)
        *6(-[@{b2}](-[::120,.4,,,draw=none]\fplus)-=-=-)
      }%
    }{\cmpd{wheland-komplex}}
    \chemmove{
      \draw[elmove]
        (b1) .. controls +(180:8mm) and +(180:8mm) .. (b2) ;
    }
    \arrow(.base west--.base east)%
      {->[+ \chemfig{AlCl_3|^{\fminus}-[@{b3}:90]Cl}][\ch{- HCl}]}[180]
    \chemmove{
      \draw[elmove]
        (b3) .. controls +(30:8mm) and +(90:12mm) .. (H) ;
    }
    \chemname{%
      \chemfig{
        R-[:30](
          -[:90,,,,rddbond]O
          -[:45,,,,dotted]\chemabove{Al}{\fdelm}Cl_3
        )
        (-[:160,.4,,,draw=none]\fdelp)
        -[:-30]*6(-=-=-=)
      }%
    }{\cmpd{acyl-AlCl3}}
    \arrow(.base west--.base east){->[\ch{+ H2O}]}[180]
    \chemname{%
      \chemfig{
        R-[:30](=[:90]O)
        -[:-30]*6(-=-=-=)
      }%
    }{\cmpd{acyl}}
  \schemestop
  \caption{Friedel-Crafts-Acylierung}
\end{scheme}

\end{document}