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Facile Two‐Step Synthesis of 1,10‐Phenanthroline‐Derived Polyaza[7]helicenes with High Fluorescence and CPL Efficiency
Author(s) -
Otani Takashi,
Tsuyuki Ami,
Iwachi Taiki,
Someya Satoshi,
Tateno Kotaro,
Kawai Hidetoshi,
Saito Takao,
Kanyiva Kyalo Stephen,
Shibata Takanori
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201700507
Subject(s) - helicene , intramolecular force , chemistry , fluorescence , phenanthroline , amination , hypervalent molecule , luminescence , aniline , reagent , photochemistry , combinatorial chemistry , crystallography , stereochemistry , molecule , organic chemistry , materials science , physics , optoelectronics , quantum mechanics , catalysis
A facile two‐step synthesis of aza[7]helicenes possessing a 6‐5‐6‐6‐6‐5‐6 skeleton from commercially available 2,9‐dichloro‐1,10‐phenanthroline via double amination with aniline derivatives followed by hypervalent iodine reagent‐mediated intramolecular double‐NH/CH couplings was developed. Single‐crystal X‐ray analyses of the helicenes revealed unique structures, including both a significantly twisted center and planar terminals of the skeleton. The azahelicenes show high fluorescent quantum yields ( Φ s) under both neutral ( Φ : 0.25–0.55) and acidic conditions ( Φ : up to 0.80). An enantiomerically pure aza[7]helicene showed high circularly polarized luminescence (CPL) activity under both neutral and acidic conditions ( g lum : up to 0.009).