Synthesis, structural, and photophysical properties of the first member of the class of pyrene-based [4]helicenes

Hu, Jian Yong; Feng, Xing; Paudel, Arjun; Tomiyasu, Hirotsugu; Rayhan, Ummey; Thuéry, Pierre; Elsegood, Mark R.J.; Redshaw, Carl; Yamato, Takehiko

Abstract

A convenient route to a new class of pyrene-based [4]helicenes is presented. Wittig reaction of 7-tert-butyl-1,3-dimethyl-5-formylpyrene with benzyltriphenylphosphonium salts in the presence of nBuLi afforded 7-tert-butyl-1,3-dimethyl-5-(phenylethenyl)pyrenes, from which 4,5-naphthalene annulated aromatic [4]helicenes, namely 7-tert-butyl-1,3-dimethyl-13- methoxydibenzo[ij,no]tetraphene and 7-tert-butyl-1,3,12,14- tetramethyldibenzo[ij,no]tetraphene, were obtained by photoinduced intramolecular cyclization. The chemical structures of these [4]helicenes were determined on the basis of their elemental analyses and spectroscopic data. The helicity in the synthesized [4]helicene induced by the presence of the second methyl group in the fjord region is discussed in detail. The photophysical and electrochemical properties of these newly developed [4]helicenes were fully investigated by UV/Vis absorption and photoluminescence spectrphotometry, and cyclic voltammetry (CV), and the crystal structures were determined for two examples. A convenient route to a new class of pyrene-based [4]helicenes is presented along with their optoelectronic properties. The introduction of two methyl groups in the fjord region of the [4]helicene gives a more distorted structure and leads to a remarkable redshift of the absorption band. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Citation

Hu, J. Y., Feng, X., Paudel, A., Tomiyasu, H., Rayhan, U., Thuéry, P., Elsegood, M. R., Redshaw, C., & Yamato, T. (2013). Synthesis, structural, and photophysical properties of the first member of the class of pyrene-based [4]helicenes. European Journal of Organic Chemistry, 2013(26), 5829-5837. https://doi.org/10.1002/ejoc.201300487

• Journal Article Type: Article
• Online Publication Date: Aug 1, 2013
• Publication Date: Sep 1, 2013
• Deposit Date: Jun 8, 2022
• Journal: European Journal of Organic Chemistry
• Print ISSN: 1434-193x
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 2013
• Issue: 26
• Pages: 5829-5837
• DOI: https://doi.org/10.1002/ejoc.201300487
• Public URL: https://hull-repository.worktribe.com/output/3621945