Tan, Q. et al. Enantioselective synthesis of a chiral nitrogen-doped buckybowl. Nat. Commun. 3:891 doi: 10.1038/ncomms1896 (2012).
The authors synthesized triazasumanene enantioselectively. They found
that the incorporation of the three nitrogen atoms in the bowl increased
the bowl depth relative to the all-carbon sumanene. This increase in
depth also increased the energy barrier to inversion of the bowls.
Sumanene undergoes rapid bowl inversion at room temperature, causing
racemization. However, triazasumanene only shows any enantiomeric
conversion after heating at 200 degrees for 12 hours.