Bending a photonic wire into a ring

Researchers from Professor Harry Anderson’s group, in collaboration with Professor Fernanda Duarte and Professor Laura Herz (Oxford Physics), and scientists from the University of Nottingham, have reported the synthesis of a 24-porphyrin ring that mimics the light-harvesting arrays of chlorophyll molecules responsible for photosynthesis.

They report the synthesis of a macrocycle in which meso-meso linked porphyrin rods have been bent into a ring. Oligomers of this type are known as “photonic wires” and they have long been regarded as rod-like. This is the first demonstration that molecular templates can bend them into rings. These nanorings exhibit two types of intramolecular energy migration: (a) from the central template to the peripheral ring of porphyrins and (b) from the 24 porphyrins to a butadiyne-linked segment of the nanoring. The kinetics of both processes have been characterised using ultra-fast time-resolved fluorescence spectroscopy. The second process is extremely fast and about 30% of the energy is transferred within the time-resolution of the experiment (350 fs). This is the first synthetic light-harvesting system to exhibit such fast energy migration on this length scale without π-conjugation between the component chromophores.

Read the full paper in Nature Chemistry.

Read the highlight in Chemical and Engineering News.