1. 3,14-Bis(4-formylphenyl)-17,17-di(n-pentyl)tetrabenzo[a,c,g,i]fluorene showing solvatochromism and crystallochromism in fluorescence.
- Author
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Ueki, Masanori, Kimura, Yusuke, Yamamoto, Yuma, Nishida, Jun-ich, Kitamura, Chitoshi, Tanaka, Mirai, Ikeda, Hiroshi, and Kawase, Takeshi
- Subjects
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BIPHENYL compounds , *SOLVATOCHROMISM , *FLUORESCENCE , *METHOXYCARBONYL compounds , *HELICAL structure , *DENSITY functional theory - Abstract
The substituent effect on optical properties of 3,14-diphenyl-17,17-di( n -pentyl)tetrabenzofluorene derivatives bearing electron-withdrawing groups (NC, CH 3 OCO, CH 3 SO 2 , and OHC) at 4-position of the phenyl groups were investigated. These compounds were readily prepared by using Suzuki–Miyaura cross-coupling as a key step. The 4-cyano, 4-methoxycarbonyl, and 4-methylsulfonyl derivatives display intense blue to blue-green fluorescence in CH 2 Cl 2 and in the solid states. On the other hand, the title compound forms two polymorphs, and thus, exhibit crystallochromism in fluorescence; the prismatic crystal emits intense yellow fluorescence, and the other crystal form does blue-green fluorescence. Moreover, the compound shows large solvatofluorochromism (Δ λ EM = 67 nm). The crystallographic analysis of the prismatic crystal reveals that the tetrabenzofluorene moiety of the compound possesses a helical structure with a C 2 symmetry and the molecules form a herringbone-like structure. The density function theory calculations predict the remarkable intramolecular charge-transfer character of the compound. The prediction is in good agreement with the observed fluorescence properties. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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