Hydrated chlorophyll a oligomers in solutions, monolayers, and thin films

Bogumil Zelent, Judith Gallant, Alexander G. Volkov, Maya I. Gugeshashvili, Gaétan Munger, Heidar Ali Tajmir-Riahi, Roger M. Leblanc

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9 Scopus citations

Abstract

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.

Original languageEnglish (US)
Pages (from-to)1-11
Number of pages11
JournalJournal of Molecular Structure
Volume297
Issue numberC
DOIs
StatePublished - Aug 13 1993
Externally publishedYes

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ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy
  • Organic Chemistry
  • Inorganic Chemistry

Cite this

Zelent, B., Gallant, J., Volkov, A. G., Gugeshashvili, M. I., Munger, G., Tajmir-Riahi, H. A., & Leblanc, R. M. (1993). Hydrated chlorophyll a oligomers in solutions, monolayers, and thin films. Journal of Molecular Structure, 297(C), 1-11. https://doi.org/10.1016/0022-2860(93)80152-L