关键词: 激光闪光光解, 瞬态吸收光谱, 联苯, NO₃自由基, 电荷转移复合物

NO₃ radical produced in the laser flash photolysis of cerium ammonium nitrate was applied to attack biphenyl in oxygen-free acetonitrile solution. The transient intermediates were identified with the nanosecond transient spectroscopic analysis and the final products were detected by GC-MS technique. A rea-sonable mechanism of the reaction was proposed. With a second-order rate constant of 8.24×10⁹ L·mol^-1·s^-1, NO₃ radical withdrew an electron from the biphenyl molecule to produce a charge-transfer (C-T) complex, which was sequentially transformed to σ- or p-nitrobiphenyl by elimination of a hydroxyl radical. The total first-order decay rate constant of the C-T complex was determined to be 2.30×10⁵ s^-1.

Key words: laser flash photolysis, transient absorbance spectrum, biphenyl, NO₃ radical, charge-transfer complex