Synthesis, structural characterization, and electrochemical studies of nickel porphyrins bearing two peripheral conjugated chelating groups

This Article describes the synthesis of several new nickel porphyrins bearing peripheral chelating groups conjugated with the macrocyclic pi system. These monomeric nickel porphyrins display quite unusual chromophoric properties, some of them absorbing in the near-infrared region. Extension of the aromatic core of the porphyrin was realized by connecting meso-aryl groups with pyrroles by ketone functionalities. Further functionalizations led to bisenaminoketones or bisenaminothioketones, which are useful building blocks for the elaboration of oligomeric porphyrins linked by metal ions. All new compounds were studied by electrochemistry, some of them showing up to six electron transfers and/or splitting of the first oxidation wave.