Photoionization of phenothiazine (PTH) and reactions of the solvated electron with some electron accepters were studied with steady state and time-resolved EPR and transient optical absorption techniques. Time-resolved EPR spectra from the phenothiazine cation radical (PTH .(+)) and hydrated electron (e(aq)(-)) formed in sodium 1-dodecylsulfate (SDS) micellar solution were observed in emission. By contrast, PTH .(+) formed by photoionization of PTH in alcohols gives absorptive EPR signals. The spin polarization carried by the hydrated electron in SDS solutions can be transferred effectively to a stable nitroxyl free radical 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl (N .(-)) present in the bulk aqueous phase. EPR and flash photolysis measurements show that this electron spin polarization transfer process proceeds with a rate which is approximately five times faster than the chemical reaction between e(aq)(-) and N .(-). The marked difference in rates is attributed to differences in spin-statistical factors and difference in reaction radii for spin exchange compared to reaction. In alcohol solutions of PTH and a nitroxyl stable radical (2,2,6,6-tetramethylpyperidin-1-oxyl, TEMPO), excitation of PTH also results in emissive polarization of the EPR spectrum of the stable radical. In this case the polarization is produced by the interaction between PTH triplets and TEMPO (doublet-triplet radical pair CIDEP). Trapping of e(aq)(-) produced by photoionization of PTH in SDS solution by electron accepters such as acrylamide and chlorophenols yields free radicals whose formation was monitored with time-resolved EPR and flash photolysis.