## Resum

An approach was developed to determine triplet quantum yields, Φ_{T}, which overcomes most of the difficulties usually encountered in flash photolysis studies of triplet states. The combined application of near-IR emission and optoacoustics yields Φ_{T} values which are independent of the absorption properties of the triplets. Thus, the triplet energies derived from near-IR phosphorescence spectra together with the values of the heat stored by the triplets determined from optoacoustic experiments afforded Φ_{T} = 0.3 ± 0.1 for porphycene (PO) and 0.4 ± 0.1 for its tetra-n-propyl derivative (TPrPO). Several calorimetric references for optoacoustic measurements in the red region were tested. The Φ_{T} values, combined with flash photolysis data, yielded accurate triplet- minus ground-state absorption coefficients. The quantum yields for singlet molecular oxygen production determined by time-resolved phosphorescence were Φ_{Δ} = 0.34 ± 0.05 for PO and 0.36 ± 0.03 for TPrPO which implies an efficiency near unity for O_{2}(^{1}Δ_{8}) production upon collision of the triplet states of the porphycenes with ground-state O_{2}.

Idioma original | Anglès |
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Pàgines (de-a) | 5879-5883 |

Nombre de pàgines | 5 |

Revista | Journal of Physical Chemistry |

Volum | 94 |

Número | 15 |

DOIs | |

Estat de la publicació | Publicada - 1990 |

Publicat externament | Sí |