An undecacyclic carbon-centered hydrocarbon radical: synthesis and investigation

• Ali S. Acan,
• Johannes Werner and
• Joachim Podlech

Beilstein J. Org. Chem. 2026, 22, 1196–1204, doi:10.3762/bjoc.22.95

• triradical contribution to the electronic ground state. Notably, the five-membered rings, particularly the central ring, exhibits pronounced antiaromatic character. Keywords: aromaticity; cyclopenta-fused polyaromatic hydrocarbons; DFT calculations; radicals; Introduction Polyaromatic hydrocarbons (PHs) [1

• cyclopenta-fused polyaromatic hydrocarbons (CP-PAHs or CPPAs) [14][15][16][17], as non-alternant conjugated polycyclic hydrocarbons (CPHs) [18][19], or are classified as compounds featuring quinoidal conjugated units. Since the first report of the triphenylmethyl radical 1 by Gomberg (Figure 1) [20][21