Dansylated Nitrile N-Oxide as the Fluorescent Dye Clickable to Unsaturated Bonds without Catalyst.

Fluorescent polymeric materials have been exploited in the fields of aesthetical purposes, biomedical engineering, and three-dimensional printing applications.  While the fluorescent materials are prepared by the polymerization of fluorescent monomer or the blending a fluorescent dye with common polymer, the covalent immobilization of fluorescent dye onto common polymers is not the practical technique.  In this paper, dansylated nitrile N-oxide (Dansyl-NO) has been designed and synthesized to be a stable nitrile N-oxide as the derivative of 2-hydroxy-1-naphthaldehyde.  While Dansyl-NO shows good reactivity to an alkene and an alkyne to give fluorescent Dansyl-Ene and Dansyl-Yne, respectively, it hardly reacts to a nitrile.  The results indicate that Dansyl-NO serves as a fluorescent dye clickable to alkenes and alkynes.  To know the effects of solvent on the fluorescent properties, the UV-vis and fluorescence spectra of Dansyl-Ene are measured in three solvents.  Dansyl-Ene shows fluorescent solvatochromism, which appears to be red-shifted along with the increase in solvent polarity.  Poly(styrene-co-butadiene) directly reacts with Dansyl-NO to give fluorescent modified SB.  The emission spectrum of modified SB is blue-shifted compared with that of Dansyl-Ene.  The blue-shift could be possibly attributed to the presence of less polar polymer skeleton around the dansyl moieties of modified SB.

Informations de copyright

© 2024 Wiley-VCH GmbH.