Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5218966 | Tetrahedron | 2013 | 8 Pages |
Zinc 31-hydroxy-131-oxo-chlorins 1-3 possessing a 12-crown-4, 15-crown-5, and 18-crown-6 ether at the 17-propionate residue were synthesized and self-assembled in aqueous and non-polar organic media. Zn chlorins 1-3 exhibited red-shifted Qy absorption bands and large CD signals around 730Â nm in an aqueous solution after standing for 2Â h or 2 days, indicating the formation of their oligomeric self-aggregates as in chlorosomes of green photosynthetic bacteria. Incubation for 2 weeks decreased the absorption bands around 730Â nm, accompanying an appearance of the absorption band around 675Â nm. These show that Zn chlorins 1-3 finally formed thermodynamically stable anti-parallel dimers in the aqueous solution. 176-Epimerically pure 1-3 exhibited essentially the same spectral properties as the corresponding epimeric mixtures, but larger CD signals were observed around 730Â nm in the spectra of epimerically pure 1 and 2 after standing for 2Â h or 2 days than those of their epimeric mixtures. In a non-polar organic solvent, Zn chlorins 1-3 formed less time-dependent chlorosomal self-aggregates that exhibited Qy absorption bands around 735Â nm.
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