Structural, redox and excited-state properties of a suite of meso-fluorinated phenyl Zn porphyrins

Zn(II) porphyrins bearing meso -phenyl groups with 1–4 fluoro-substitution have been synthesized and structurally characterized by single-crystal X-ray crystallography. Together with the known Zn(II) tetra-phenyl and Zn(II) pentafluorophenyl porphyrins, this homologous series of porphyrins enable a comprehensive description of the solid-state, solution and excited state properties of the tetrapyrrolic ring bearing meso -aryl groups with varying degrees of fluorination. Unlike fluoro-substitution at the β -position of the pyrrole ring, we show that increasing fluorination of the meso -phenyl groups of the Zn(II) porphyrin ring can occur without significantly changing steady state absorption and emission spectra and degrading the excited state properties of the porphyrin. Such increased fluorination may be beneficial to photo- therapeutic, −diagnostic and -imaging applications in biomedicine.