Osamu IWANAGA

<jats:p>New μ-OH-μ-O<jats:sub>2</jats:sub>-Co(<jats:sc>iii</jats:sc>)<jats:sub>2</jats:sub> complexes with 6-hpa ligand were synthesized and structurally characterized. The 6-hpa ligand facilitates O–O bond formation to enhance the catalytic activity in O<jats:sub>2</jats:sub> evolution <jats:italic>via</jats:italic> electrochemical water oxidation.</jats:p>

Abstract meso‐Unsubstituted (meso‐free) porphyrins have been an effective platform for creating versatile peripherally functionalized porphyrins and directly‐linked porphyrin oligomers. The synthetic strategy has been extended to produce meso‐free porphyrinoids including carbaporphyrins, core‐modified porphyrins, ring‐contracted, and ring‐expanded porphyrins. meso‐Free porphyrinoids can serve as a benchmark for demonstrating the inherent physical properties and stabilities, free from the influences of substituents, thereby highlighting the significance of these porphyrinoid classes.