Multichromophoric cyclodextrins. 4. Light conversion by antenna effect

Journal Article · Wed Jun 12 04:00:00 EDT 1996 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja954332t· OSTI ID:282961

Jullien, L ^[1]; Canceill, J; Lehn, J M; Marchi-Artzner, V ^[1]; Bardez, E; Lefevre, J P ^[2]; Lefevre, J P ^[2]

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1. College de France, Paris (France)
2. Conservatoire National des Arts et Metiers, Paris (France)

A water soluble {beta}-cyclodextrin (CD-NA) bearing seven naphthoyl chromophores forms very stable 1:1 complexes with a merocyanine laser dye DCM-OH (4-dicyanomethylene)-2-methyl-6-(p-(bis(hydroxyethyl)amino)-styryl)-4H-pyran. The antenna effect, i.e. energy transfer from the naphthoyl antenna chromophores to the encased dye, is shown to occur with 100% efficiency. The stability of the complexes is very high (K{sub s} = 10{sup 5}) owing to the contribution of the naphthoate residues. The structural features of the complexes have been examined in detail: circular dichroism experiments confirm the expected axial orientation of DCM-OH in the cavity of CD-NA, and fluorescence anisotropy measurements together with {sup 13}C-NMR longitudinal relaxation time measurements show that the complex formed between CD-NA and DCM-OH is tight. The mechanisms of homotransfer (i.e., between naphthoate chromophores) and heterotransfer (i.e., from naphthoate chromophores to DCM-OH included in the cavity) are discussed in light of existing theories. In both cases, the major contribution arises more likely from Coulombic interaction than from short-range interactions. Such multichromophoric cyclodextrins are good models for mimicry of the antenna function in photosynthesis and show great promise as photochemical microreactors. 38 refs., 11 figs., 3 tabs.

• OSTI ID: 282961
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 23 Vol. 118; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
40 CHEMISTRY
ABSORPTION SPECTRA
COMPLEXES
DEXTRIN
DYES
ENERGY CONVERSION
ENERGY TRANSFER
FLUORESCENCE
NMR SPECTRA
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS