As a new kind of cationic photoinitiator, iron-arene complex has received much attention in recent years. The authors have reported the synthesis of cyclopentadienyl-iron-arene complexes and their activities in initiating the photopolymerization of epoxides. Up to now, the photolysis process of ironarene complex has not been thoroughly investigated. In this The authors have reported the synthesis of cyclopentadienyl-iron-arene complexes and their activities in initiating the photopolymerization of epoxides. Up to now, the photolysis process of ironarene complex has not been thoroughly investigated. In this