REACTIONS OF ELECTRONS GENERATED IN PHOTOLYSIS OF PYRENE ON SILICA-GEL SURFACE

Photoirradiation of degassed pyrene (Py)/silica gel samples at -196-degrees-C induces electron transfer showing Py+.. Existence of photogenerated electrons (e(tr)-) is confirmed by the ensuing reactions. Warming the sample initiates a recombination of e(tr)- with Py+. showing thermoluminescence, and introduction of O2 into the photoirradiated sample leads to the formation of O2-., observed by EPR. The time-resolved studies show short-lived Py+., indicating that most Py'', after initial generation, recombine with e(tr)-.