氯苯嘧啶醇在有机溶剂中的光化学降解研究

研究了3种光源下氯苯嘧啶醇在正己烷、丙酮、甲醇、乙腈、异丙醇中的光化学降解.结果表明,在高压汞灯下氯苯嘧啶醇在5种有机溶剂中光解迅速,光解半衰期分别为8.73、288.81、26.87、4.25和16.54 min;在紫外灯下光解半衰期分别为4.25、10.65、3.87、2.46和3.09 h;在太阳光下,光解半衰期分别为4.88、20.62、14.29、3.30和13.83 h;太阳光下氯苯嘧啶醇在水中光解迅速,半衰期仅为6.13 h,但丙酮的存在对氯苯嘧啶醇光解有显著光猝灭作用,当水中丙酮的含量为2%时,猝灭效率高达159.30%.光解反应体系的吸收光谱表明,氯苯嘧啶醇在液相的光解率的差异与吸收光谱的改变有一定程度的相关性,但吸收光谱并不能完全解释光解速率的差异.

Photodegradation of fenarimol in various solvents

The photodegradation of fenarimol in various solvents under 3 kinds of light sources was studied.In hexane,acetone,methanol,acetonitrile,and isopropanol,the photolytic rates of fenarimol were rapid.The halflives of fenarimol were 8.73,288.81,26.87,4.25 and 16.54 min respectively under high pressure mercury lamp;4.25,10.65,3.87,2.46 and 3.09 h respectively under UV light,4.88,20.62,14.29,3.30 and 13.83 h respectively under sunlight.It was found that the photolysis of fenarimol was rapid when it was irradiated by sunlight.The photolysis of fenarimol in water could be restrained by acetone.The photoquench rate was found distinctly related to quantity of acetone.The photolytic mechanism was also discussed.The photolytic rate of fenarimol has connection with the absorption spectrum of solution.