In order to investigate the possible coordination of both bismuth(III) and lead(II) by porphyrins for an application in alpha-radioimmunotherapy, several series of functionalized bismuth porphyrins have been synthesized and their stabilities in acidic medium were compared.Where unfunctionalized porphyrins are not suitable for such a purpose, strapped hanging carboxylate porphyrins are stable and allow a rapid coordination of both bismuth and lead. This property could lead to the preparation of an in-situ generator of alpha particles by a pre-complexation of 212 lead, the radioactive parent of 212 bismuth, in the ligand.