title: meso-Aryl [28]Hexaphyrin Silicon Complexes Bearing Various Si-Substituents and 1,16-Dihydrohexaphyrin bis-Chlorosilicon Complex.
abstract: Herein, the synthesis of Möbius aromatic [28]hexaphyrin silicon complexes bearing various Si-substituents from reactions of [28]hexaphyrin 1 with suitable silicon sources in the presence of a base is reported. Si-substituents newly introduced are vinyl (4), phenyl (6), hydroxy (7), and hydride groups (8). X-ray crystallographic analysis of complexes 6 and 7 has shown trigonal bipyramidal penta-coordinated silicon atoms, which are favorable for the hexaphyrin ligands to take on smoothly twisted Möbius conformations. N-fused Si-vinyl complex 5 was also isolated and structurally well characterized. Through these studies, the Si-substituent effect has been shown to be relatively small. Reaction of 1 with HSiCl3 in CH2Cl2 gave 1,16-dihydrohexaphyrin bis-chlorosilicon complex 9, probably through intramolecular hydride transfer from the silane to the pyrrolic α-carbon.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan.
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Ishida
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan. osuka@kuchem.kyoto-u.ac.jp.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Osuka
keywords: Möbius aromaticity; porphyrins; silane reduction; silicon complexes; substituent effects