title: Fluorescence enhancement of pyrene chromophores induced by alkyl groups through σ-π conjugation: systematic synthesis of primary, secondary, and tertiary alkylated pyrenes at the 1, 3, 6, and 8 positions and their photophysical properties.
abstract: We have systematically synthesized 1-, 3-, 6-, and 8-alkyl-substituted pyrene derivatives using the latest synthesis methods and investigated the effects of alkyl substitution on the photophysical properties of the pyrene chromophore. Like the trimethylsilyl group, which is known to enhance the fluorescence properties of some chromophores through σ*-π* conjugation, alkyl groups (primary, secondary, and tertiary) enhanced the fluorescence quantum yield of the pyrene chromophore through σ-π conjugation in most cases. While these enhancements in the fluorescence quantum yield were beyond expectations, the results were supported by absolute measurements. These results also indicate that ubiquitous alkyl groups can be used to tune the photophysical properties of the pyrene chromophore, as well as to improve the solubility or prevent aggregation. In other words, they can be used to develop new photofunctional materials.
authors: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Tokyo 152-8552, Japan.
authors: Yosuke
authors: Y
authors: Niko
authors: Susumu
authors: S
authors: Kawauchi
authors: Shun
authors: S
authors: Otsu
authors: Katsumi
authors: K
authors: Tokumaru
authors: Gen-ichi
authors: G
authors: Konishi
mesh_terms: D000478:Alkylation; D005453:Fluorescence; D015394:Molecular Structure; D055668:Photochemical Processes; D011721:Pyrenes / Q000138:chemical synthesis* / Q000737:chemistry*; D011789:Quantum Theory; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011721:Pyrenes; C030984:pyrene