THE PHOTODEGRADATION REACTION OF SOME PORPHYRINS
Abstract:
<p align="justify"> One of the most important but undesirable properties of the porphyrins is their oxidative photodegradation which can occur in non-polar solvents, under irradiation, and in the presence of molecular oxygen. The mechanism of this oxidative photodegradation implies singlet oxygen and different radical species. This paper is concerned with the mechanism of the photodegradation of some meso-tetra(4-X-phenyl)porphyrins(TXPP) and meso-tetra(4-X-1-naphtyl)porphyrins(TXNP), where X could have different organic structures (-NH<sub>2</sub>,-N0<sub>2</sub>,-S0<sub>3</sub>H,-OH,-OCH<sub>3</sub>,-CH<sub>3</sub>). Based on different spectral methods (UV-Vis and IR absorption spectroscopy, emission spectroscopy, X-ray diffraction, electronic microscopy, and mass spectrometry, we propose a photodegradation mechanism, and we evaluated the effect of some scavengers (2,6-di-tert-butyl-phenol (DTBF) for radical species, 1,3-diphenylisobenzofuran (DPBF) for singlet oxygen and nitro-blue tetrazolium (NBT) for superoxide anion) during the porphyrin photodegradation. </p>
<p align="justify"> One of the most important but undesirable properties of the porphyrins is their oxidative photodegradation which can occur in non-polar solvents, under irradiation, and in the presence of molecular oxygen. The mechanism of this oxidative photodegradation implies singlet oxygen and different radical species. This paper is concerned with the mechanism of the photodegradation of some meso-tetra(4-X-phenyl)porphyrins(TXPP) and meso-tetra(4-X-1-naphtyl)porphyrins(TXNP), where X could have different organic structures (-NH<sub>2</sub>,-N0<sub>2</sub>,-S0<sub>3</sub>H,-OH,-OCH<sub>3</sub>,-CH<sub>3</sub>). Based on different spectral methods (UV-Vis and IR absorption spectroscopy, emission spectroscopy, X-ray diffraction, electronic microscopy, and mass spectrometry, we propose a photodegradation mechanism, and we evaluated the effect of some scavengers (2,6-di-tert-butyl-phenol (DTBF) for radical species, 1,3-diphenylisobenzofuran (DPBF) for singlet oxygen and nitro-blue tetrazolium (NBT) for superoxide anion) during the porphyrin photodegradation. </p>
DOI: 10.48141/SBJCHEM.v5.n5.1997.109_1997.pdf
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