π-Extended Nitrogen-Doped Molecular Bowls Comprising Adjacent Pentagons.

While the classical buckybowls, such as corannulene, and sumanene, have been extensively investigated, research on other molecular bowls containing double neighboring pentagonal rings remains underdeveloped. Here we present the synthesis of nitrogen-doped molecular bowls incorporating adjacent pentagonal motifs with an extended π-conjugated surface. Their molecular curvatures are preserved according to the analyses of bowl-depth, π-orbital axis vector angles, and inversion energy barrier when compared to those of their parent structures. The extended π-conjugation induces the bathochromic shifts of both absorption and emission spectra, the narrowed energy gaps of the frontier molecular orbitals, as well as the enhanced aromatic character in the fused pentagonal rings. Furthermore, the extended aromatic surface enables the binding with fullerene C in solution.