“…2a,2b,6b,6c-Tetrahydrobenzo(a)cyclopropa(ca)pentalene-6C-carbonitrile, 4, crystallizes in P2 1 2 1 2 1 with Z′ = 1 and bears the nitrile substituent at the central apical sp 3 site C6C. In dinitrile variant 2a,2b,6b,6c-tetrahydrobenzo(a)cyclopropa(ca)pentalene-1,2dicarbonitrile, 11 (Pbca, Z′ = 2), the cyano groups are located on sp 2 C atoms of the cage edge rather than the apical sp 3 . It crystallizes with two ordered molecules in the asymmetric unit which have very similar geometries, the dimensions of which are presented comparatively in Table 2 (as 11 1 and 11 2 ); only one is shown in Figure 2b.…”