Microwave synthesis of cationic ABAB di-imidazolyl fluorinated porphyrins and manganese complexes

Abstract

ABAB porphyrins are promising platforms for potential use in several applications, particularly in medical imaging. Herein, the synthetic optimization studies for preparing such porphyrins via the statistical condensation of 4-trifluoromethylphenyl and 1-methylimidazol-2-yl aldehydes with pyrrole, are described, with emphasis on the use of microwave irradiation as heating source, against conventional heating. Then, the preparation of the corresponding Mn(III) complex and cationization of the imidazole groups, using microwave irradiation, were also carried out and the photophysical, photochemical, and electrochemical properties were further assessed. The compounds revealed interesting features, including adequate log P, singlet oxygen yield, redox potentials, and excellent photostability, which pave the way for potential use as imaging probes in MRI or PET, or as photosensitizing molecules.