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Heteroannulenes 1 and 3 containing three subunits of isoindole or pyrrole,
respectively, three 1,3,4-thiadiazole moieties, and six aza-bridges have be
en synthesized by reaction of the corresponding diiminoisoindoline or diimi
nopyrroline with 2,5-diamino-1,3,4-thiadiazole. These conjugated nonaromati
c 30 pi -electron macrocycles coordinate three metal ions within their cent
ral cavity and constitute one of the rare examples of expanded heteroazapor
phyrinoids.