Vyacheslav Diev - Porphyrins Fused with Unactivated Polycyclic Aromatic Hydrocarbons

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      Publication Details (including relevant citation   information):

      J. Org. Chem., 2011, Article ASAP,   DOI: 10.1021/jo201490y


      A systematic study of the preparation of porphyrins with extended   conjugation by meso,β-fusion with polycyclic aromatic   hydrocarbons (PAHs) is reported. The meso-positions of   5,15-unsubstituted porphyrins were readily functionalized with   PAHs. Ring fusion using standard Scholl reaction conditions   (FeCl3, dichloromethane) occurs for   perylene-substituted porphyrins to give a porphyrin   β,meso annulated with perylene rings (0.7:1 ratio of   syn and anti isomers). The naphthalene, pyrene,   and coronene derivatives do not react under Scholl conditions but   are fused using thermal cyclodehydrogenation at high   temperatures, giving mixtures of syn and anti  isomers of the meso,β-fused porphyrins. For   pyrenyl-substituted porphyrins, a thermal method gives   synthetically acceptable yields (>30%). Absorption spectra of   the fused porphyrins undergo a progressive bathochromic shift in   a series of naphthyl (λmax = 730 nm), coronenyl   (λmax = 780 nm), pyrenyl (λmax = 815 nm),   and perylenyl (λmax = 900 nm) annulated porphyrins.   Despite being conjugated with unsubstituted fused PAHs, the   β,meso-fused porphyrins are more soluble and processable   than the parent nonfused precursors. Pyrenyl-fused porphyrins   exhibit strong fluorescence in the near-infrared (NIR) spectral   region, with a progressive improvement in luminescent efficiency   (up to 13% with λmax = 829 nm) with increasing degree   of fusion. Fused pyrenyl-porphyrins have been used as broadband   absorption donor materials in photovoltaic cells, leading to   devices that show comparatively high photovoltaic efficiencies.

      Address (URL): http://pubs.acs.org/doi/abs/10.1021/jo201490y