Japanese researchers working with Atsuhiro Osuka have taken up this challenge - successfully. They have been able to develop a highly promising approach to the construction of molecular wires that conduct light. Porphyrins are an important component of enzymes, such as the hemoglobin that renders our blood red. As part of the chlorophyll in plants, porphyrins are fundamentally involved in photosynthesis. They help the plant make chemical use of the sun s energy.
Porphyrins are stable, ring-shaped molecules with a strictly planar structure.
Osuka and his colleagues have managed to get up to 128 of these building blocks hooked together. But this length is far from the limit. We are already very successfully constructing much longer porphyrin chains. The electrons in the individual building blocks are in a strong, long-ranging interaction with each other. If the electrons of one ring are excited by absorption of a photon, that is by light energy, they pass the excitation on to the next building block.