Toward photoswitchable dendritic hosts. Interaction between azobenzene- functionalized dendrimers and eosin
Articolo
Data di Pubblicazione:
1998
Citazione:
Toward photoswitchable dendritic hosts. Interaction between azobenzene- functionalized dendrimers and eosin / A. Archut, G.C. Azzellini, V. Balzani, L. De Cola, F. Vogtle. - In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. - ISSN 0002-7863. - 120:47(1998 Dec 02), pp. 12187-12191. [10.1021/ja9822409]
Abstract:
Two poly(propyleneimine) dendrimers bearing up to 32 photoisomerizable azobenzene groups in the periphery have been used as potential hosts for eosin Y (2',4',5',7'-tetrabromofluorescein dianion). The all-E azobenzene dendrimers can be reversibly switched to their Z form by light excitation. Both the E and Z forms of the dendrimers quench the eosin fluorescence by a static mechanism. The quenching is most likely due to an electron-transfer reaction between the singlet excited state of eosin and the tertiary amine units present along the branches of the dendrimers. Quenching by the Z form of the dendrimers is more efficient than quenching by the E form. The E → Z and Z → E photoisomerization reactions of the azobenzene units of the dendrimers are sensitized by eosin via a triplet-triplet energy transfer mechanism. The results obtained indicate that eosin is hosted by the dendrimers and suggest that the Z forms are more efficient hosts than the E forms.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
A. Archut, G.C. Azzellini, V. Balzani, L. De Cola, F. Vogtle
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