Fig. 3. Optimized molecular structure and Newman projections along each C–N axis (approximate). The three distinguishable conformations of S-1,5-diamino-[4]cumulene are shown. The ± denotes the plus or minus configuration of the pseudo dihedral angle (approximately ±110°) measured at C C–N–lone-pair, and the S/R denotes the axial chirality of the molecule.
