Thephotochemicalpropertiesofpolypropylviologen(PPrV)-cationexchangeableresincomplexeswerestudies.Thecolorofthesecomplexeschangedtobluewhenirradiatedbyamercurylamp.UVandESRstudiesindicatedthatanefficientviologenradicalaccumulationoccursinPPrV-resincomplexes.Anexplanationforthestablephotoinducedredicalaccumulationisproposed.