Tp. Causgrove et al., OPTICAL SPECTROSCOPY OF A HIGHLY FLUORESCENT AGGREGATE OF BACTERIOCHLOROPHYLL-C, Journal of physical chemistry, 97(21), 1993, pp. 5519-5524
Bacteriochlorophyll (BChl) c and a similar model compound, Mg-methyl b
acteriopheophorbide d, form several types of aggregates in nonpolar so
lvents. One of these aggregates is highly fluorescent, with a quantum
yield higher than that of the monomer. This aggregate is also unusual
in that it shows a rise time in its fluorescence emission decay at cer
tain wavelengths, which is ascribed to a change in conformation of the
aggregate. An analysis of fluorescence depolarization data is consist
ent with either a linear aggregate of four or five monomers or prefera
bly a cyclic arrangement of three dimers.