Thiadiazole-derived expanded heteroazaporphyrinoids.

[structure: see text] Heteroannulenes 1 and 3 containing three subunits of isoindole or pyrrole, respectively, three 1,3,4-thiadiazole moieties, and six aza-bridges have been synthesized by reaction of the corresponding diiminoisoindoline or diiminopyrroline with 2,5-diamino-1,3,4-thiadiazole. These conjugated nonaromatic 30 pi-electron macrocycles coordinate three metal ions within their central cavity and constitute one of the rare examples of expanded heteroazaporphyrinoids.