Multichromophoric phthalocyanine-(perylenediimide)(8) molecules: a photophysical study.

We describe the synthesis of a series of phthalocyanine (Pc)-perylenediimide (PDI)(8) "octad" molecules, in which eight PDI moieties are attached to a Pc core through alkyl-chain linkers. There is clear spectroscopic evidence that these octads can exist as non-aggregated "monomers" or form aggregates along the Pc cores, depending on the type of Pc and the solvent medium. In the low dielectric constant solvents, into which the octads are soluble, photoexcitation of the PDI units leads to rapid energy transfer to the Pc centre, rather than a charge separation between moieties.