Functionalization of 5,15-Diphenylporphyrin: Preparation and X-Ray Crystal Structures of meso Nitro, Bromo, and Trimethylsilylethynyl Derivatives

Substitutions on 5,15-diphenylporphyrin led to the isolation of mono- and di-bromo and mono- and di-nitro derivatives, which were converted into their respective nickel(II) complexes. Reaction of the bromoporphyrins with iodine/silver nitrite resulted in nitrodebromination as well as conventional nitration. The nickel(II) complex of 5-nitro-10,20-diphenylporphyrin was reduced to the 5-amino derivative. The nickel(II) complexes of the bromoporphyrins were converted into the respective mono- and bis-(trimethylsilylethynyl) species. The crystal structures of 5-nitro-10,20-diphenylporphyrin, 5-bromo-10,20-diphenylporphyrinatonickel(II), and 10,20-diphenyl-5-(trimethylsilylethynyl)porphyrinatonickel(II) were determined.