Protected Newkome-type second-generation dendrimers (based on Lin's amine) were
synthesized with a pyrene moiety attached to the core. The photophysical property in aqueous solution
of the protected dendrimers shows self-association behavior in water. Pyrene excimer emission at 475
nm is observed in water even at very low concentrations of protected dendrimer (ca. 5 × 10-8 M). This
emission band is absent in other solvents even up to a concentration of 10-5 M. The corresponding
unprotected dendrimer does not show the pyrene excimer fluorescence. The amide of pyrene butyric acid
with tert-butylamine shows the formation of excimer, albeit with very low intensity. Quenching studies
on the dendrimer with hydrophilic quencher iodide anion (I-) reveal that there is significant quenching
of fluorescence intensity in the case of N-tert-butyl-4-pyren-1-ylbutyramide as compared to that of the
pyrene-attached second-generation protected dendrimer. This shows that the pyrene moiety in the case
of the protected dendrimer is significantly shielded from the surrounding.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.