Nickel and palladium complexes of seco-tribenzoporphyrazines derived from one-pot condensation of 1,3-diiminoisoindoline

Unexpected formation of seco-tribenzoporphyrazines from nickel- or palladium-template macrocyclization reaction of 1,3-diiminoisoindoline as a sole starting material has opened a novel access to this class of molecules. Seco-tribenzoporphyrazines exhibit strongly-split Q band absorption, basically typical of tetraazachlorin-like electronic structures, which are discussed in detail based on UV–Vis absorption and magnetic circular dichroism spectroscopies and theoretical calculations.