title: Regioisomer-Free C 4h β-Tetrakis(tert-butyl)metallo-phthalocyanines: Regioselective Synthesis and Spectral Investigations.
abstract: Metal β-tetrakis(tert-butyl)phthalocyanines are the most commonly used phthalocyanines due to their high solubility, stability, and accessibility. They are commonly used as a mixture of four regioisomers, which arise due to the tert-butyl substituent on the β-position, and to the best of our knowledge, their regioselective synthesis has yet to be reported. Herein, the C 4h -selective synthesis of β-tetrakis(tert-butyl)metallophthalocyanines is disclosed. Using tetramerization of α-trialkylsilyl phthalonitriles with metal salts following acid-mediated desilylation, the desired metallophthalocyanines were obtained in good yields. Upon investigation of regioisomer-free zinc β-tetrakis(tert-butyl)phthalocyanine using spectroscopy, the C 4h single isomer described here was found to be distinct in the solid state to zinc β-tetrakis(tert-butyl)phthalocyanine obtained by a conventional method.
authors.affiliation: Department of Frontier Materials, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, Japan.
authors.forename: Norihito
authors.initials: N
authors.lastname: Iida
authors.affiliation: Department of Frontier Materials, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, (Japan).
authors.forename: Etsuko
authors.initials: E
authors.lastname: Tokunaga
authors.affiliation: System Instruments Co., Ltd 776-2, Komiya-cho, Hachioji, Tokyo, 192-0031, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Frontier Materials, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, Japan ; Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology Gokiso, Showa-ku, Nagoya, 466-8555, (Japan).
authors.forename: Norio
authors.initials: N
authors.lastname: Shibata
keywords: aggregation; phthalocyanines; protecting groups; regioselectivity; silicon; synthesis