Facile formation of a benzopyrane-fused [28]hexaphyrin that exhibits distinct Möbius aromaticity.
A benzopyrane-fused [28]hexaphyrin, 2, was prepared by simple heating of [26]hexaphyrin 1 in acetic acid. Fused [28]hexaphyrin 2 features a molecular twist, a distinct diatropic ring current, a large HOMA value, a large negative NICS value, and a large two-photon absorption (TPA) cross section even at room temperature, all of which support the Möbius aromaticity of 2. To the best of our knowledge, 2 is the first macrocycle that acquires distinct Möbius aromaticity without any assistance from metal coordination, temperature control, or protonation.
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Sumito
S
Tokuji
Jae-Yoon
JY
Shin
Kil Suk
KS
Kim
Jong Min
JM
Lim
Katsuyuki
K
Youfu
Shohei
S
Saito
Dongho
D
Kim
Atsuhiro
A
Osuka