Oligo(p-phenylene ethynylene)-BODIPY derivatives: synthesis, energy transfer, and quantum-chemical calculations.
Chemistry
; 17(47): 13247-57, 2011 Nov 18.
Article
em En
| MEDLINE
| ID: mdl-21989923
ABSTRACT
The synthesis and energy-transfer properties of a series of oligo(p-phenylene ethynylene)-BODIPY (OPEB) cassettes are reported. A series of oligo(p-phenylene ethynylene)s (OPEs) with different conjugated chain lengths as energy donor subunit in the energy-transfer system were capped at both ends with BODIPY chromophores as energy-acceptor subunits. The effect of the conjugated chain of OPEs on energy transfer in the OPEB cassettes was investigated by UV/Vis and fluorescence spectroscopy and modeling. With increasing number n of phenyl acetylene units (n=1-7), the absorption and emission maxima of OPEn are bathochromically shifted. In the OPEBn analogues, the absorption maximum assigned to the BODIPY moieties is independent of the length of the OPE spacer. However, the relative absorption intensity of the BODIPY band decreases when the number of phenyl acetylene units is increased. The emission spectra of OPEBn are dominated by a band peaking at 613â
nm, corresponding to emission of the BODIPY moieties, regardless of whether excitation is at 420 or 550â
nm. Furthermore, a very small band is observed with a maximum between 450 and 500â
nm, and its intensity relative to that of the BODIPY emission increases with increasing n, that is, the excited state of OPE subunits is efficiently quenched in OPEBn by energy transfer to the BODIPY moieties. Energy transfer (ET) from OPEn to BODIPY in OPEBn is very efficient (all Φ(ET) values are greater than 98 %) and only slightly decreases with increasing length of the OPE units. These results are supported by theoretical studies that show very high energy transfer efficiency (Φ(ET) >75 %) from the OPE spacer to the BODIPY end-groups for chains with up to 15-20 units.
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MEDLINE
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Alcinos
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Idioma:
En
Revista:
Chemistry
Assunto da revista:
QUIMICA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Bélgica