title: Conformational Fixation of a Rectangular Antiaromatic [28]Hexaphyrin Using Rationally Installed Peripheral Straps.
abstract: A rectangular [28]hexaphyrin bearing outer straps at the long side has been synthesized by SN Ar reaction of [26]hexaphyrin with allyl alcohol, intramolecular olefin metathesis by using Hoveyda-Grubbs second-generation catalyst, and reduction with NaBH4 . The peripheral straps enforce a rectangular conformation for the [28]hexaphyrin, which shows Hückel antiaromatic character, as confirmed by its planar X-ray structure, a strong paratropic ring current, characteristic UV/Vis/NIR absorption features, small electrochemical HOMO-LUMO gap, and very fast S1 decay.
authors: Department of Physical Chemistry, Graduate School of Pharmaceutical Sciences, Chiba University, Chuoh-Inohana, Chiba, 260-8675, Japan. yoneda@faculty.chiba-u.jp.
authors: Tomoki
authors: T
authors: Yoneda
authors: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea.
authors: Taeyeon
authors: T
authors: Kim
authors: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
authors: Takanori
authors: T
authors: Soya
authors: Department of Physical Chemistry, Graduate School of Pharmaceutical Sciences, Chiba University, Chuoh-Inohana, Chiba, 260-8675, Japan.
authors: Saburo
authors: S
authors: Neya
authors: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea.
authors: Juwon
authors: J
authors: Oh
authors: Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea. dongho@yonsei.ac.kr.
authors: Dongho
authors: D
authors: Kim
authors: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan. osuka@kuchem.kyoto-u.ac.jp.
authors: Atsuhiro
authors: A
authors: Osuka
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D008968:Molecular Conformation; D011166:Porphyrins / Q000737:chemistry*
chemical_list: D000475:Alkenes; D011166:Porphyrins
keywords: Hückel antiaromaticity; Hückel aromaticity; conformational fixation; hexaphyrins; olefin metathesis