Design of Novel Pyrene-Bodipy Dyads: Synthesis, Characterization, Optical Properties, and FRET Studies.

Pasquale Porcu,Andrea Ruiu,Mireille Vonlanthen,Ernesto Rivera,Israel González-Méndez

doi:10.3390/molecules23092289

Pasquale Porcu, Andrea Ruiu + Show 3 more

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https://doi.org/10.3390/molecules23092289

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Abstract

A new series of dendronized bodipys containing pyrene units was synthesized and characterized. Their optical and photophysical properties were determined by absorption and fluorescence spectroscopy. This series includes three different compounds. The first one has an anisole group linked to the bodipy unit, which was used as the reference compound. In the second, the bodipy core is linked to a zero generation dendron with one pyrene unit. The third compound contains a first generation Fréchet-type dendron bearing two pyrene units. In this work, the combination pyrene-bodipy was selected as the donor-acceptor pair for this fluorescence resonance energy transfer (FRET) study. Doubtless, these two chromophores exhibit high quantum yields, high extinction coefficients, and both their excitation and emission wavelengths are located in the visible region. This report presents a FRET study of a novel series of pyrene-bodipy dendritic molecules bearing flexible spacers. We demonstrated via spectroscopic studies that FRET phenomena occur in these dyads.

Highlights

The development of new photoactive compounds bearing donor-acceptor groups has very relevant in materials science [1,2,3]
Bodipy (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dyes have attracted the attention of many research groups due to its special photophysical properties
The purification of the products was performed by column chromatography in silica gel and the elution was checked by thin layer chromatography (TLC)

Summary

Introduction

The development of new photoactive compounds bearing donor-acceptor groups has very relevant in materials science [1,2,3]. The fluorescence resonance energy transfer (FRET) phenomenon is a non-radiative process that includes the energy transfer between two molecules or two different groups in a molecule [6,7,8,9,10,11,12]. The FRET phenomenon occurs via a Förster mechanism when the emission spectra of the donor group overlap, partially or totally, with the absorption spectra of the acceptor. Bodipy (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) dyes have attracted the attention of many research groups due to its special photophysical properties. They present a strong ultraviolet (UV) absorption, relatively sharp fluorescence peaks with high quantum yields, and very good photostability [13,14,15,16,17]. The main aspect that make bodipy dyes photophysically suitable is the tunable emission/absorption by functionalization [19,20]

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