Thiazolyl- and bithiazolyl-substituted porphyrins have been characterized to assess their potential as new standards for singlet molecular oxygen photosensitization. Their absorption, fluorescence, phosphorescence and triplet-triplet spectra are slightly red-shifted relative to those of tetraphenylporphine (TPP), a well-established singlet molecular oxygen standard.
Likewise, the singlet and triplet lifetimes, as well as the fluorescence quantum yields are roughly one order of magnitude smaller than those of TPP, while the triplet and singlet oxygen quantum yields increase concomitantly to ca. 1.