Porphyrinoid Macrocycles Based on Thiophene—The Octaethyltetrathiaporphyrin Dication

Abstract

As a model compound in the thiaporphyrin series, the perchlorate of the dication 1 is ideal because of its favorable solubility properties. The key step in its synthesis is the acid-induced condensation (not biomimetic!) of 3,4-diethyl-2-hydroxymethylthiophene that affords the tetra- as well as the pentacyclocondensation product. The latter product opens a route to the 22π pentathiapentaphyrin trication 2, the sulfur analog of pentaphyrin.