Chlorophyll(Chl)-a derivatives containing some rigid linkers in the C3-substituent, inserted between a hydroxymethyl group and a zinc 131-oxo-chlorin moiety, were synthesized as models of bacteriochlorophyll-c/d/e molecules in the main light-harvesting antennae (chlorosomes) of photosynthetic green bacteria. These model compounds were synthesized from a C3-ethynylated Chl-a derivative via several coupling reactions, and the lengths of the linkers were controlled by ethynylene and p-phenylene groups. In less polar organic solvents or an aqueous micellar solution, some derivatives self-aggregated in a J-type fashion similar to that observed in natural chlorosomes, which was confirmed with UV/Vis absorption and CD spectroscopies. Their self-aggregation abilities were dependent on the length of the inserted linkers and the conformation of the propargylic/benzylic alcoholic hydroxy groups.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Physical and Theoretical Chemistry
- Organic Chemistry