TY - JOUR
T1 - Hydrated chlorophyll a oligomers in solutions, monolayers, and thin films
AU - Zelent, Bogumil
AU - Gallant, Judith
AU - Volkov, Alexander G.
AU - Gugeshashvili, Maya I.
AU - Munger, Gaétan
AU - Tajmir-Riahi, Heidar Ali
AU - Leblanc, Roger M.
N1 - Funding Information:
This work was supportedb y grants from the Natural Sciencesa nd EngineeringR esearchC oun-cil of Canada (NSERC) and the Fonds pour la Formation de Chercheurse t 1’Aidea la Recherche (FCAR). Financial supporta s postgraduates cho-larshipsc amef rom FCAR and from La Fondation CEU (UQTR) to J.G.
PY - 1993/8/13
Y1 - 1993/8/13
N2 - The interfacial tension measurements of dry and wet chlorophyll a at an octane-water interface show differences in adsorption behavior of the pigment depending on its aggregation state. Optical properties were also investigated using absorption and Fourier transform-infrared spectroscopy, along with fluorescence (excitation and emission) measurements in non-polar solvents and in thin films. The absorption and fluorescence spectral characteristics, and fluorescence lifetime measurements of dry and wet samples clearly indicate the difference in aggregation properties of this photosynthetic pigment. A strong decrease in the energy of Qy electronic transitions (Δν = 1700cm-1), due to the formation of hydrated oligomers, was accompanied by a decrease in fluorescence lifetime from 5.75 ± 0.02 ns (diluted dry chlorophyll a in n-hexane) to 0.12 ± 0.03 ns (wet chlorophyll a in thin films). Discussion of these results is based on the key role of the central magnesium atom in the porphyrin ring in intermolecular interactions and self-organization of chlorophyll a molecules.
AB - The interfacial tension measurements of dry and wet chlorophyll a at an octane-water interface show differences in adsorption behavior of the pigment depending on its aggregation state. Optical properties were also investigated using absorption and Fourier transform-infrared spectroscopy, along with fluorescence (excitation and emission) measurements in non-polar solvents and in thin films. The absorption and fluorescence spectral characteristics, and fluorescence lifetime measurements of dry and wet samples clearly indicate the difference in aggregation properties of this photosynthetic pigment. A strong decrease in the energy of Qy electronic transitions (Δν = 1700cm-1), due to the formation of hydrated oligomers, was accompanied by a decrease in fluorescence lifetime from 5.75 ± 0.02 ns (diluted dry chlorophyll a in n-hexane) to 0.12 ± 0.03 ns (wet chlorophyll a in thin films). Discussion of these results is based on the key role of the central magnesium atom in the porphyrin ring in intermolecular interactions and self-organization of chlorophyll a molecules.
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U2 - 10.1016/0022-2860(93)80152-L
DO - 10.1016/0022-2860(93)80152-L
M3 - Article
AN - SCOPUS:0011451552
VL - 297
SP - 1
EP - 11
JO - Journal of Molecular Structure
JF - Journal of Molecular Structure
SN - 0022-2860
IS - C
ER -