The synthesis of new heterocyclic oligo(phenylene) analogues based on soluble, nonaggregating 1,2-diazines is reported. Improved palladium-catalyzed reductive coupling methods were developed to allowfor the preparation of large quantities of iptycene-derived bipyridazines
and biphthalazines,
and thecontrolled synthesis of well-defined oligomers up to sexipyridazine. Crystallographic, spectroscopic,
andcomputational evidence indicate that in these analogues, hindrance at the ortho position is relaxed relativeto poly(phenylenes). The resulting building blocks are promising for incorporation in conjugated electronicsmaterials,
and as new iptycene-derived lig
ands for transition metals.
