Direct β-to-β linked branched and cyclic porphyrin trimers and pentamers have been synthesized by the Suzuki–Miyaura coupling of β-borylporphyrins and β-bromoporphyrins. The cyclic porphyrin trimer, the smallest directly linked cyclic porphyrin wheel to date, and its twined pentamer, exhibit small electrochemical HOMO–LUMO gaps, broad nonsplit Soret bands, and red-shifted Q-bands, thus indicating large electronic interactions between the constituent porphyrin units.
Direct β-to-β linked branched and cyclic porphyrin trimers and pentamers have been synthesized by the Suzuki–Miyaura coupling of β-borylporphyrins and β-bromoporphyrins. The cyclic porphyrin trimer, the smallest directly linked cyclic porphyrin wheel to date, and its twined pentamer, exhibit small electrochemical HOMO–LUMO gaps, broad nonsplit Soret bands, and red-shifted Q-bands, thus indicating large electronic interactions between the constituent porphyrin units.