화학공학소재연구정보센터
Journal of Physical Chemistry A, Vol.108, No.39, 8002-8008, 2004
Hydrogen atom formation in the photolysis of acetone at 193 nm
An experimental and theoretical study of the formation of hydrogen atom in the photolysis of acetone at 193 nm is reported. The H atom photofragments are detected by the technique of vacuum ultraviolet laser-induced fluorescence (VUV-LIF) spectroscopy at 121.6 nm. The quantum yield for H atom formation from acetone photolysis at 193 nm is determined to be 0.039 +/- 0.006. The Doppler profiles of the H atom photofragments are measured by scanning the probe laser wavelength around the resonance frequency of the H atom at 121.6 nm. The nascent kinetic energy distribution of the H atom fragments is found to be characterized by a Maxwell-Boltzmann function with the temperature of 5000 K. The spatially isotropic recoil distribution in the H atom photofragmentation is observed. The potential energy surfaces for the H atom formation processes from acetone photolysis are examined using molecular orbital calculation methods. Atmospheric implications of the present result are briefly discussed.