The signal of a nitrogen-centered radical adduct of DMPO was observed. The results obtained indicate that the trapped radical is a cation radical of diamine produced from diamine and photogenerated hole. 观察到DMPO与氮中心自由基加合物的ESR信号,表明捕捉到的自由基是脂二胺与光生空穴作用而产生的胺的阳离子自由基。