Preparation and photochemistry of some tetrazaporphins
Abstract
Photo-oxidation of metal octaphenyltetrazaporphin pigments gave phenanthrenedicarboximide (VI). The initial oxidation of the magnesium analogue was reversible and the metal-free pigment was also isolated on irradiation of solutions of this pigment. Some tetraphenanthrotetrazaporphin pigments have been synthesised and their structures have been proved by oxidation to give phenanthrenedicarboximide.