Absorption flattening as one cause of distortion of circular dichroism spectra of Delta-RuPhen(3) . H(2)TPPS complex

To extend the model that explains why and how much absorption flattening
(AF) influences circular dichroism (CD) signals, we have investigated the interesting
case of exciton CD in the Soret region of a noncovalent complex formed by (DRuPhen3)
21 and the tetraanionic porphyrin H2TPPS. Different concentrations have been
studied by using an AF emulator and spectra simulation. The CD spectra of this compound
occasionally show distortions in the solution sampling mode with the increase of
concentration; the inhomogeneous distribution in the cell volume is due to aggregation
and is the source of the AF effect. On the basis of these results, we conclude that AF is
an important cause of distortions in CD spectra for D-RuPhen3 H2TPPS complexes and
might affect the CD bands of other aggregated systems as well