Molecules, Vol. 24, Pages 4083: Unusual Fluorescence Behavior of Pyrene-Amine Containing Dendrimers

Molecules, Vol. 24, Pages 4083: Unusual Fluorescence Behavior of Pyrene-Amine Containing Dendrimers Molecules doi: 10.3390/molecules24224083 Authors: Andrea Ruiu Mireille Vonlanthen Sandra M. Rojas-Montoya Israel González-Méndez Ernesto Rivera A new class of pyrene-based dendrimers, characterized by the presence of a 1,4,7,10-Tetraazacyclododecane (cyclen) unit as the core, was studied by SSF (steady-state fluorescence) and SPC (single-photon counting fluorescence). The photophysical behavior of these dendrimers was studied in THF, DMF and DMSO solution. The typical signals for pyrene-labeled molecules were recorded in each solvent, showing the representative fluorescence spectra: the corresponding emissions of monomer and excimer of the pyrene chromophore are observed. Unexpectedly, the typical quenching of tertiary amine on the pyrene emission was not observed in these dendrimers. Quenching studies were performed by adding up to 3 equivalents of trifluoroacetic acid (TFA). To our knowledge, this is the first report of pyrene’s unquenching behavior by a tertiary amine.
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research