Regioselective bromination of (Tetraphenyltetrabenzoporphyrinato)palladium(II). Synthesis of a new octabromo derivative of the tetraphenyltetrabenzoporphyrin series

Abstract

Bromination of (meso-tetraphenyltetrabenzoporphyrinato)palladium(II) with bromine in the presence of tetramethylammonium bromide occurs exclusively at the benzene rings fused to the porphyrin system while the phenyl rings in the meso positions are not involved. The corresponding octabromo-substituted complex was obtained using a large excess of bromine on prolonged reaction time. The complex was isolated and characterized by 1H NMR spectra, electronic absorption spectra in the UV and visible regions, and MALDI-TOF mass spectra. It was assigned the structure of symmetric (22,23,72,73,122,123,172,173-octabromo-5,10,15,20-tetraphenyltetrabenzoporphyrinato)palladium(II).