The photoinitiated cationic polymerization of cyclohexene oxide with N-phenacyl-N,N-dimethylanilinium hexafluoroantimonate (PDA(+)SbF6(-)) and a poly-nuclear aromatic compound, such as perylene, anthracene or phenothiazine, or an aromatic carbonyl compound, such as benzophenone or thioxanthone, was studied at lambda(inc) > 340 nm. All the aromatic sensitizers except benzophenone and thioxanthone are effective in initiating the polymerizatior at wavelengths where PDA(+)SbF(6)(-) is transparent. An initiation mechanism is proposed that involves electron transfer from the excited sensitizer to PDA(+)SbF(6)(-).