Surface-attachable porphyrins and corroles with varied singlet oxygen generation for photodynamic applications

Porphyrinoids are important molecular species due to their unique structure and photo- and electrochemical properties, including photochemical generation of singlet oxygen ( 1 O 2 ). Covalent attachment of porphyrinoids to surfaces has potential applications in photodynamic therapy, photodynamic inactivation, chemical inactivation, and electrochemistry; established methods of attachment are limited to very specific substrates. In this work, six porphyrinoids bearing diazirine, a functional group capable of facile insertion into C–H, O–H, or N–H bonds, at one or more meso positions, were synthesized. The impact of structure on 1 O 2 quantum yield (Φ Δ ) both in solution and on surfaces was evaluated, and those with the highest Φ Δ were also assessed indirectly using 9,10-anthracenediyl-bis(methylene)dimalonic acid (ADMA) as a 1O2 detector molecule. Zinc(II) 5,10,15,20-tetrakis((N-4-[3-(trifluoromethyl)-3H-diazirin-3- yl]benzyl)-4-pyridyl)-21H,23H-porphine (Zn-DZTPP) and 5,10,15,20-tetrakis((N-4-[3-(trifluoromethyl)- 3H-diazirin-3-yl]benzyl)-4-pyridyl)-21H,23H-porphine (H 2 -DZTPP) showed the highest Φ Δ at 0.90 and 0.74, respectively, of the compounds tested, and retained 1 O 2 generating activity after being covalently bonded to a polyethylene terephthalate (PET) surface.