Ultrafast spectroscopic investigation of discrete co-assemblies of a Zn-porphyrin–polymer conjugate with a hexapyridyl template

One of the key features of biological light harvesting complexes (LHCs) is their incorporation of multichromophoric reaction centres via non-covalent interactions. Most synthetic mimics require relatively complex syntheses and are constructed in organic solvents. Here, we report the use of polymer self-assembly to enable the formation of Zn-porphyrin–pyridine complexes in aqueous solution. Time-resolved femtosecond pump–probe spectroscopy revealed four time constants, each associated with significant ground state bleach recovery, suggesting energy transfer between the porphyrin and pyridine. Self-assembly opens up new photophysical relaxation pathways, making it a useful additional strategy for the construction of more advanced LHC mimics.