Monoreduced 1,2-dihydrocorannulene versus the parent corannulene

The monoanion of dihydrogenated corannulene isolated in the form of its potassium salt, namely tris(diglyme-κ(3)O,O',O'')potassium hexacyclo[11.5.2.0(4,17).0(7,16).0(10,15).0(14,18)]icosa-1,3,5,7(16),8,10(15),11,13,17-nonaenide, [K(C6H14O3)3](C20H12), has been structurally characterized for the first time. The X-ray study confirms the previous NMR spectroscopic prediction that the two H atoms are attached to the same six-membered ring to form 1,2-dihydrocorannulene, thus destroying the aromaticity of only one arene ring of the corannulene core. The direct comparison of (C20H12)(-) with the parent corannulene anion, (C20H10)(-), is provided to illustrate the geometry perturbations caused by rim hydrogenation.