Supramolecular assemblies composed of porphyrin and fullerenes exhibit unique photochemical properties that differ from those of the individual components. These properties arise from the non-covalent interactions between the porphyrin and fullerene units, which lead to the formation of donor-acceptor complexes. Some of the specific photochemical properties observed in these supramolecular assemblies include:1. Enhanced light-harvesting capabilities: Porphyrins are known for their strong light absorption in the visible region, while fullerenes exhibit absorption in the ultraviolet region. When combined in a supramolecular assembly, the overall light-harvesting capability is enhanced due to the complementary absorption profiles of the two components.2. Charge separation and transfer: Upon photoexcitation, the porphyrin molecule can transfer an electron to the fullerene molecule, resulting in the formation of a charge-separated state. This process is facilitated by the close proximity and favorable orientation of the donor porphyrin and acceptor fullerene units in the supramolecular assembly. The charge-separated state can persist for a longer time compared to the individual components, which is beneficial for applications such as solar energy conversion and photocatalysis.3. Modulation of photophysical properties: The non-covalent interactions between porphyrin and fullerene units can lead to changes in the photophysical properties of the individual components, such as fluorescence lifetimes and quantum yields. For example, the fluorescence of porphyrin can be quenched in the presence of fullerene due to the formation of the charge-separated state.4. Formation of excimer or exciplex states: In some supramolecular assemblies, the excited states of porphyrin and fullerene can interact to form excimer excited dimer or exciplex excited complex states. These states exhibit distinct photophysical properties, such as red-shifted emission spectra and longer lifetimes, compared to the individual components.In summary, supramolecular assemblies composed of porphyrin and fullerenes exhibit unique photochemical properties that arise from the non-covalent interactions between the two components. These properties, such as enhanced light-harvesting capabilities, charge separation and transfer, modulation of photophysical properties, and formation of excimer or exciplex states, differ from those of the individual porphyrin and fullerene molecules and can be exploited for various applications in materials science and energy conversion.