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Title: Single-photon ionization of pyrene and anthracene giving trapped electrons in alkali-metal-cation-exchanged zeolites X and Y. A direct time-resolved diffuse reflectance study

Journal Article · · Journal of Physical Chemistry; (USA)
DOI:https://doi.org/10.1021/j100155a002· OSTI ID:5761005

Time-resolved diffuse reflectance spectroscopy is used to investigate the photolysis of anthracene- or pyrene-impregnated alkali-metal-cation-exchanged zeolite X and Y with a nitrogen laser (337 nm). The studies suggest that anthracene or pyrene molecules are distributed in at least two different sites (active and nonactive) in the zeolite X and Y. Excitation of anthracene or pyrene adsorbed in nonactive sites produces singlet excited states of anthracene or pyrene, which can either be photoionized by absorbing a second photon or decay to the triplet excited states through intersystem crossing; however, anthracene or pyrene adsorbed in active sites is photoionized through a single-photon process. The products of the photoionization are cation radicals of arene and trapped electrons (e.g., Na{sub 4}{sup 3+} for NaY). The broad absorption band for the trapped electron is around 550 nm for both NaX and NaY; around 620 nm for both LiX and LiY and around 710 nm for KX.

OSTI ID:
5761005
Journal Information:
Journal of Physical Chemistry; (USA), Vol. 95:2; ISSN 0022-3654
Country of Publication:
United States
Language:
English