Characterization of Push-Pull-Type Benzo[X]quinoline Derivatives (X = g or f): Environmentally Responsive Fluorescent Dyes with Multiple Functions

J Org Chem. 2020 Oct 16;85(20):13177-13190. doi: 10.1021/acs.joc.0c01878. Epub 2020 Oct 1.

Abstract

Benzo[X]quinoline (X = g or f: BQX) derivatives bearing bis-trifluoromethyl and amine groups have been designed as push-pull-type fluorescent dyes. Through the synthesis of BQX derivatives from 2,7-diaminonaphthalene, linear-type (BQL) and angular-type (BQA) structural isomers were obtained. X-ray structures of single crystals from six given BQX derivatives revealed that the BQL and BQA series adopt planar- and bowl-shaped structures. In the fluorescence spectra, interestingly, the BQL series emitted in the near-infrared region over 700 nm in polar solvents. Based on the visible absorptions and base properties related to the amine moiety, the ammonia responsiveness was investigated using an ion-exchange reaction by the BQX-HCl salt. By exploiting the environmentally responsive fluorescence probe, cell imaging through confocal laser microscopy was conducted using HeLa and 3T3-L1 cells, emitting specific lipid droplets. The results indicate that BQX derivatives have multiple functions and may be applied in materials chemistry and biochemistry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fluorescent Dyes*
  • HeLa Cells
  • Humans
  • Microscopy, Confocal
  • Quinolines*
  • Spectrometry, Fluorescence

Substances

  • Fluorescent Dyes
  • Quinolines