Near-infrared fluorescein dyes containing a tricoordinate boron atom. Issue 33 (12th July 2019)

• Record Type: Journal Article
• Authors: Ando, Naoki; Soutome, Hiroki; Yamaguchi, Shigehiro
• Is Part Of: Chemical science. Volume 10:Issue 33(2019)
• Page Start: 7816
• Page End: 7821
• Publication Date: 2019-07-12
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9sc02314c
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Tricoordinate boron imparts near-infrared absorption/emission and unusual multi-stage changes in the photophysical properties to fluorescein dyes. Abstract : Bora-fluoresceins (BF s), fluorescein analogues containing a tricoordinate boron atom instead of an oxygen atom at the 10-position of the fluorescein skeleton, were synthesized as a new family of fluorescein analogues. The deprotonatedBF s exhibited absorption and fluorescence in the near-infrared region, which were significantly red-shifted relative to those of hitherto-known heteroatom-substituted fluorescein analogues on account of the orbital interaction between the tricoordinate boron atom and the fluorescein skeleton.BF s also showed multi-stage changes resulting from a Lewis acid–base equilibrium at the boron center in combination with a Brønsted acid–base equilibrium at the phenolic hydroxy group.