97179-94-7Relevant articles and documents
Observation and Interpretation of Annulated Porphyrins: Studies on the Photophysical Properties of meso-Tetraphenylmetalloporphyrins
Rogers, Joy E.,Nguyen, Kiet A.,Hufnagle, David C.,McLean, Daniel G.,Su, Weijie,Gossett, Kristi M.,Burke, Aaron R.,Vinogradov, Sergei A.,Pachter, Ruth,Fleitz, Paul A.
, p. 11331 - 11339 (2003)
We present results of a joint computational and experimental study for a series of annulated metalloporphyrins in order to establish structure-property relationships. Specifically, we have examined the effects of substitution by meso-tetraphenylation, tetrabenzo and tetranaphtho annulation, and effects of changing the central metal from zinc (Zn) to palladium (Pd). Utilizing absorption and emission spectroscopy and laser flash photolysis techniques, the photophysical properties of these porphyrins have been determined. Upon the addition of benzo or naphtho groups, we observed an overall red shift in the ground state absorption spectra of both the B-bands and the Q-bands with increased conjugation and an increase in the Q-band to B-band intensity ratios. Time-dependent density functional theory calculations were performed on both series of porphyrins to identify the effects of phenyl, benzo, and naphtho substituents on the spectra. The benzo and naphtho adducts provide a larger contribution (typically 40-90%) to the observed red shifts due to increased π-conjugation, while there is a smaller contribution (typically 0-25%) from distortion of the porphyrin. Similarly, a red shift for the T1-T n absorption spectrum and an overall general broadening in the spectrum were found with increased conjugation. An increase in the triplet molar extinction coefficient through the near-infrared region with annulation was also found. Varying the metal has an effect on the overall absorption spectra; i.e., the ground state spectra of the Zn porphyrins are red-shifted relative to the Pd porphyrins. For the triplet excited state spectra there were small effects in the spectra by changing the metal with a significant contribution to the kinetic properties by the heavy atom effect of the Pd.
Relationship between the photochemical properties and structure of pophyrins and related compounds
Kuznetsova,Gretsova,Kalmykova,Makarova,Dashkevich,Negrimovskii,Kaliya,Luk'yanets
, p. 133 - 140 (2007/10/03)
Photostability was studied and quantum yields of singlet oxygen in air-saturated dimethyl sulfoxide were determined for phenyl-substituted zinc complexes of porphyrin and porphyrazine and their annelated analogs. It is found that the photochemical properties of the complexes are stronger affected by linear annelation of the macroring than its angular annelation. In whole benzene annelation in the macroring of porphyrins reduce their photostability and quantum yield of singlet oxygen, while phenyl substitution favors generation of singlet oxygen.
