X-ray characterization of core-modified N-confused fused porphyrinogen and genesis of π(σ) (anti)aromatic N-confused fused porphyrinoids†

Rational synthesis, spectroscopic and solid-state structural isolation of an unprecedented core modified N-confused fused porphyrinogen 7 as a single isomer has been achieved in near quantitative yield. The solid-state crystal structure reveals a non-planar structure as a result of four sp³ meso carbons for 7. All possible stereoisomers of the S₂N₃ hybrid N-confused fused porphyrinogen 7 have been unravelled via DFT studies. The genesis of the porphyrinogen-porpho(mono/di)methene-porphyrin skeleton rearrangements has been unravelled using controlled chemical oxidation methods. The σ and π (anti)aromaticity of the porphyrinoids 9 and 10 have been thoroughly investigated via spectroscopic and in-depth DFT studies.