The unprecedented strong paratropic ring current of a bis-Pd^II complex of 5,10,23-trimesityl [28]heptaphyrin(1.1.0.0.1.0.0).

ABSTRACT: Acid-catalyzed Friedel-Crafts-type cyclization of tetrapyrrolic BF₂ complex 1 and α,α'-dibromotripyrrin 2 gave 5,10,23-trimesityl [28]heptaphyrin(1.1.0.0.1.0.0) BF₂ complex 3BF₂ as a stable and moderate antiaromatic macrocycle. Demetalation of 3BF₂ with methanesulfonic acid followed by treatment with HCl gave free-base salt 3HCl that holds a chloride anion at the core. This salt displays a planar structure with an inverted pyrrole and a stronger paratropic ring current. Metalation of neutral free-base 3 with PdCl₂ gave bis-Pd^II complex 3Pd₂ as a stable antiaromatic molecule. The ¹H NMR spectrum of 3Pd₂ displays signals due to pyrrolic β-protons in the range of -1.06 ∼ -1.90 ppm, indicating th

SUBMITTER: Liu Y 

PROVIDER: S-EPMC11268459 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature