Self-aggregation of synthetic zinc chlorophyll derivative possessing a perfluoroalkyl group in a fluorinated solvent

Zinc 31-hydroxy-131-oxo-chlorin possessing a perfluoroheptyl group on the 17-propionate was prepared by modifying chlorophyll a. The synthetic compound self-aggregated in 0.1% (v/v) THF and HCFC225cb (CClF2CF2CHClF) to give similar large oligomers to natural light-harvesting antennae of green photosynthetic bacteria and their models. Visible absorption, circular dichroism, and fluorescence emission spectra showed that F–F interaction between the perfluoroheptyl side chain and the fluorinated solvent (HCFC225cb) stabilized the supramolecular structure. The core part of the supramolecular structure was constructed by a special bond of Zn⋯O31-H⋯OC131 and π–π stacking, and the 17-propionates were at the peripheral part.

Figure optionsDownload as PowerPoint slide