\documentclass{article}
\usepackage{xymtex}
\usepackage{chemist}
\pagestyle{empty}
\begin{document}

\utrigonal{0==C;2==O$^-$;3D==O;
1==\fiveheterov{4==$^+$H$_2$N}{3Sb==(yl);3Sa==H}}

\end{document}