Chemfig: fixed bond length and vertical alignment

Question

I have two reaction schemes and one is a skeletal representation. I want all of my bonds to be a certain length, so I set the option fixed length = true and atom sep=1.5em. This gives me the above formula with equal bonds, but it destroys the skeletal molecule. If I then set fixed length = false the bonds are way too short. How can I fix this?

Also, the vertical alignment of seems off (see red line).

MWE:

\documentclass[11pt, a4paper]{scrbook}
\usepackage[left=27.5mm,right=16mm,top=30mm,bottom=30mm]{geometry}
\usepackage[english,main=ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{chemfig}
\setchemfig{fixed length=false, atom sep=1.5em, arrow offset=6pt, scheme debug=false}


\begin{document}

\small
\centering
\schemestart
\chemfig{\mathit{n}}
\chemname{\chemfig{NH_2-{(}CH_2{)}_{11}-COOH}}{$\omega$-Amino-Laurylsäure}
\arrow(.mid east--.mid west)
\chemname{\chemfig{\vphantom{N}-[@{li}]{NH}-{(}CH_2{)_{11}}-CO-[@{re}]}}{Polyamid 12}
\polymerdelim[delimiters={[]}]{li}{re}
\+
\chemfig{\mathit{n}}
\chemname{\chemfig{H_2O}}{Wasser}
\schemestop

\vspace{1cm}

\schemestart
\chemfig{\mathit{n}}
\chemname{\chemfig{-[:-58]-[:20]-[:-30]-[:30]-[:-30]-[:30]-[:90](=[:30]O)-[:150]N(-[:90]H)-[:210]-[:150]-[:210]-[:160]-[:238]}}{Laurinlactam}
\arrow
\chemname{\chemfig{-[@{li}:-30]NH-[:30]-[:-30]-[:30]-[:-30]-[:30]-[:-30]-[:30]-[:-30]-[:30]-[:-30]-[:30]-[:-30](=[6]O)-[@{re}:30]}}{Polyamid 12}
\polymerdelim[delimiters={[]},height=5pt,depth=30pt]{li}{re}
\schemestop

\end{document}

Answer 1

the following code works perfectly on my pc

\documentclass[11pt, a4paper]{scrbook}
\usepackage[left=27.5mm,right=16mm,top=30mm,bottom=30mm]{geometry}
\usepackage[english,main=ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{chemfig}
\setchemfig{fixed length=true, atom sep=1.5em, arrow offset=6pt, scheme debug=false}


\begin{document}

\small
\centering
\schemestart
\chemfig{\mathit{n}}
\chemname{\chemfig{NH_2-{(}CH_2{)}_{11}-COOH}}{$\omega$-Amino-Laurylsäure}
\arrow(.mid east--.mid west)
\chemname{\chemfig{\vphantom{N}-[@{li}]{NH}-{(}CH_2{)_{11}}-CO-[@{re}]}}{Polyamid 12}
\polymerdelim[delimiters={[]}]{li}{re} 
  \+ 
\chemfig{\mathit{n}}
\chemname{\chemfig{H_2O}}{Wasser}
\schemestop

\vspace{1cm}

\schemestart
\chemfig{\mathit{n}}
\chemname{\chemfig[fixed length=false]{
        -[:-58]-[:20]-[:-30]-[:30]-[:-30]-[:30]-[:90](=[:30]O)-[:150]N(-[:90]H)-[:210]-[:150]-[:210]-[:160]-[:238]}}{Laurinlactam}
\arrow
\chemname{\chemfig{-[@{li}:-30]NH-[:30]-[:-30]-[:30]-[:-30]-[:30]-[:-30]-[:30]-[:-30]-[:30]-[:-30]-[:30]-[:-30](=[6]O)-[@{re}:30]}}{Polyamid 12}
\polymerdelim[delimiters={[]},height=5pt,depth=30pt]{li}{re}
\schemestop

\end{document}