A 1,3-phenylene-bridged hexameric porphyrin wheel and efficient excitation energy transfer along the wheel.

A 1,3-phenylene-bridged hexameric Zn(II) porphyrin wheel was synthesized by a Suzuki-Miyaura coupling reaction through a one-pot or a stepwise route. The hexameric wheel structure was revealed by using X-ray diffraction analysis. The porphyrin wheel exhibits a split Soret band due to effective exciton coupling and displays efficient excitation energy transfer along the wheel. Measurements of fluorescence anisotropy decay and pump-power-dependent decay reveal a rapid excitation energy hopping along the wheel with a rate of 1.4 ps.