Stable [48]-, [50]-, and [52]Dodecaphyrins(1.1.0.1.1.0.1.1.0.1.1.0): The Largest Huckel Aromatic Molecules

摘要

[52]Dodecaphyrin(1.1.0.1.1.0.1.1.0.1.1.0) was quantitatively oxidized with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) to the corresponding [50]dodecaphyrin. Further oxidation of [50]dodecaphyrin with MnO2 quantitatively afforded [48]dodecaphyrin. Of the three, [50]dodecaphyrin showed Huckel aromatic character as the largest aromatic molecule reported to date. Protonation of [50]dodecaphyrin with methanesulfonic acid (MSA) led to the formation of a planar tetraprotonated species that displayed a sharp and intense Soret-like band at 906nm with epsilon=6.5x10(5)M(-1)cm(-1) and Q-band-like bands at 1346 and 1600nm.