Synthesis of Ni porphyrin-Ni 5,15-diazaporphyrin hybrid tapes.

Ni porphyrin (P) and Ni 5,15-diazaporphyrin (DAP) hybrid tapes were synthesized by Suzuki-Miyaura cross-coupling reactions of - or β-borylated P with β-brominated DAP followed by intramolecular oxidative fusion reactions. -β doubly linked hybrid tapes were synthesized by oxidation of singly linked precursors with DDQ-FeCl. Synthesis of triply linked hybrid tapes was achieved by oxidation with DDQ-FeCl-AgOTf with suppression of peripheral β-chlorination. In these tapes, DAP segments were present as a 20π-electronic unit, but their local antiaromatic contribution was trivial. Remarkably, these hybrid tapes were stable and exhibited extremely enhanced absorption bands in the NIR region and multiple reversible redox waves. A pentameric hybrid tape showed a remarkably sharp and red-shifted band at 1168 nm with = 5.75 × 10 M cm. Singly linked P-DAP dyads were oxidized with DDQ-FeCl to give stable radicals, which were oxidized further to afford dimeric hybrid tapes possessing a nitrogen atom at the peripheral-side -position.