Probing radicals and reactive species in zeolites

Alkyl radicals can play an important role as intermediates in lean NO_x chemistry. This type of chemistry is of relevance to the treatment of emissions from diesel engines. Diatomic iodine provides a model system in which the dynamics and interactions of intra-zeolite species can be probed, and where photodissociation leads to two atomic radicals. A study on iodine has demonstrated the capabilities of laser induced fluorescence for monitoring photodissociation processes and the fate of the photoproducts in this system. It also sheds light on how the nanoporous environment of the zeolite can affect photodissociation processes. The polar environment of the zeolite can also stabilize states of the parent and photoproducts by interactions similar to those involving solvation. In turn, the stabilization of states can affect the emission wavelengths observed subsequent to optical excitation of such systems. This is an abstract of a paper presented at the 222nd ACS National Meting (Chicago, IL 8/26-30/2001).