Porhyrins-cyclodextrin. 1. Photooxidation of zinc tetrakis(4-sulfonatophenyl)porphyrin in cyclodextrin cavities: The characterization of ZnTSPP dication. Photolysis, radiolysis, and NMR studies. [Gamma radiation]

Journal Article · Thu Mar 21 04:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100159a021· OSTI ID:5729827

Mosseri, S; Mialocq, J C; Perly, B ^[1]; Hambright, P ^[2]

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1. Centre National de la Recherche Scientifique, Gif-sur-Yvette (France)
2. Howard Univ., Washington, DC (United States)

NMR and spectrophotometric evidence for the formation of a 4:1 cyclodextrin-zinc tetrakis(4-sulfonatophenyl)porphyrin (ZnTSPP) (CD-ZnP) complex is reported. Photolysis of CD-ZnP at 422 nm at pH = 12 was found to lead to quantitative formation (99.9%) of 1,2-dihydroxyporphyrin, which exhibits intense absorption bands at 340 and 625 nm and an emission band at 642 nm. At much lower pH the photolysis was found to lead to the efficient formation of isoporphyrin or its hydroxylated form (pK = 6.0), which possesses characteristic absorption bands in the near infrared region. The nonfluorescing isoporphyrin is converted slowly via molecular rearrangement and further hydroxylation into the fluorescing 1,2-dihydroxyporphyrin (k = 1.1 M{sup {minus}1} s{sup {minus}1}). Emission and excitation spectra of the final stable products are reported. OH{sup {sm bullet}} radical also leads to the formation (although inefficient) of 1,2-dihydroxyporphyrin as shown by {gamma}-radiolysis and pulse radiolysis experiments. Pulse radiolysis experiments in the presence of Br{sup {minus}} were carried out as well. Inhibition of the electron transfer from ZnTSPP to the Br{sub 2}{sup {sm bullet}{minus}} radical in cyclodextrin solution was observed and investigated in detail. The photophysical properties of the inclusion complex and of ZnTSPP{sup 2+} were determined by using the time-correlated single-photon-counting technique and the nanosecond laser absorption spectroscopy method. The absorption spectra of ZnTSPP{sup {sm bullet}3+} and ZnTSPP{sup 4+} are also reported.

• OSTI ID: 5729827
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:6; ISSN JPCHA; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ABSORPTION SPECTROSCOPY
ANIONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BROMINE IONS
CARBOHYDRATES
CARBOXYLIC ACIDS
CATIONS
CHARGED PARTICLES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
COBALT 60
COBALT ISOTOPES
COMPLEXES
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELECTRON TRANSFER
EMISSION SPECTROSCOPY
GAMMA RADIATION
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROXYL RADICALS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
IONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KINETICS
MAGNETIC RESONANCE
MINUTES LIVING RADIOISOTOPES
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDATION
PH VALUE
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOLYSIS
POLYSACCHARIDES
PORPHYRINS
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOISOTOPES
RADIOLYSIS
REACTION KINETICS
RESONANCE
SACCHARIDES
SPECTRA
SPECTROSCOPY
VISIBLE SPECTRA
YEARS LIVING RADIOISOT
ZINC COMPLEXES