D. Wohrle et al., PREPARATION AND PHOTOSTABILITY OF PORPHYRINS INCORPORATED INTO ALPO4-5 MOLECULAR-SIEVES BY CRYSTALLIZATION INCLUSION, Zeolites, 15(6), 1995, pp. 540-550
Catio nic porphyrins such as tetrakis(N-alkylyridyl)porphyrins 2,3, te
trakis(N-methylpyridyloxy)-phthalocyanines 5 or tetrakis(N-alkylpyrido
)tetraazaporphyrin 6,7 in either metal-free or zinc-containing forms a
re incorporated readily into AlPO4-5 molecular sieves by crystallizati
on inclusion. The dye molecules, which are much larger than the channe
l diameter of the molecular sieve, are encapsulated in mesopores as re
vealed from adsorption isotherms. The chromophores are predominantly p
resent as monomers as gleaned from u.v./vis spectra. The surprisingly
strongly enhanced photostability, in comparison to the photostability
in solution, is a direct proof for the encaged state of the porphyrins
and a fundamental prerequisite for any potential application under vi
sible light conditions.