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利用高里德堡态氢原子飞行时间 (HRTOF)探测技术 ,研究了正丙醇和异丙醇的紫外光解动力学过程 .在 193.3nm光辐射下 ,O -H键快速断裂过程构成主要的氢原子生成通道 .伴随O -H键的碎裂 ,相当大的一部分能量转换成氢原子及其相应碎片的平动能 (正丙醇〈fv〉 =0 .76 ;异丙醇〈fv〉 =0 .78) .氢原子碎片具有各向异性的角度分布 ;其角分布异向因子 β分别为 - 0 .79(正丙醇 )和 - 0 .77(异丙醇 ) .研究结果表明 ,吸收 1个 193.3nm光子后 ,丙醇分子跃迁到一个寿命很短的电子激发态 ;沿着O -H反应坐标 ,该激发态势能面是排斥的 ,因而O -H键快速断裂 .此外 ,还得到了丙醇的O -H键离解能 :(432± 2 )kJ/mol(正丙醇 )和 (433± 2 )kJ/mol(异丙醇 ) .
The kinetics of UV photolysis of n-propanol and isopropanol were investigated using the HRTF technique at high Rydberg states. The rapid quenching of O-H bonds at 193.3 nm resulted in the formation of major hydrogen Atomic generation channels. With the cleavage of the O-H bond, a significant portion of the energy is converted to the translational energy of the hydrogen atom and its corresponding fragment (n-propanol = 0.76; isopropanol = fv). 78) .Hydrocarbon fragments have an angular distribution of anisotropy, and their angular distribution anisotropy factors are -0.79 (n-propanol) and -0.77 (isopropanol), respectively.The results show that the absorption of one 193.3 After the photons of nm, the propanol molecule transited to a short-lived electron-excited state; along the O-H reaction coordinate, the potential surface of the excited state was repulsive and thus the O-H bond broke rapidly. In addition, O-H bond dissociation energies: (432 ± 2) kJ / mol (n-propanol) and (433 ± 2) kJ / mol (isopropanol).