Synthesis, characterization and photochemical properties of metallo porphyrazines substituted with alkyl linked carbazole, benzoazepine and phenothiazine moieties

Abstract

Novel octa-phenotiazine, octa-benzoazepine and octa-carbazole substituted magnesium(II) (MgPz-I-III) and zinc(II) (ZnPz-I-III) porphyrazines were synthesized from 2,3-bis[6-(4a, 10a-dihydrophenothiazin-10-yl)-hexylsulfanyl]-but-2-enedinitrile (5), 2,3-bis [6-(4a, 11a-dihydro-dibenzo[b, f] azepin-5-yl)-hexysulfan-yl]-but-2-enedinitrile (8) and 2,3-bis(6-carbazol-9-yl-hexylsulfanyl)-but-2-enedinitrile (10), respectively. These dinitrile derivatives 5, 8 and 10 were also prepared by the reaction of 1,2-dicyano-1,2-ethylenedithiolate di-sodium salt (4) with 10-(6-bromohexyl)-10H-phenothiazine (3), 5-(6-bromohexyl)-5H-diben-zo[b, f] azepine (7) and 9-(6-bromo-hexyl)-9H-carbazole (9), respectively. Porphyrazino-zinc(II) complexes were synthesized by one-step reaction using Zn(BuO)(2) as a template agent. All the novel compounds were characterized by elemental analysis and different spectroscopic methods such as H-1 NMR, C-13 NMR, FT-IR, UV-Vis and mass. The photochemical properties including photodegradation and singlet oxygen generation for magnesium(II) and zinc (II) porphyrazine complexes were studied in dimethylsulfoxide solutions for determination of their photosensitizer behaviors.