Spectroscopic and dynamic studies of the photolysis reaction of acetone by 193 nm excimer laser

The high-resolution time resolved Fourier transformed IR spectroscopy is used here to measure the emitted spectra of the CO fragment resulting from the photolysis of acetone by 193 nm excimer laser. A high-resolution IR spectra in the range of 1950-2250 cm(-1), is assigned to be CO ro-vibrational transition. The vibrational population of the first four vibrational levels were obtained by simulating of these spectra. The vibrational temperature T-Vib. of the CO was found to be 2250 +/- 70 K as given from the Boltzmann plot. Moreover, the Boltzmann distribution was found to fit the rotational degrees of freedom yielding a characteristic temperature T(Rot.)f the CO of about 2250 K in the case of low relaxation and 1 mus time delay experiment. The prior distribution model was found to predict the vibrational and rotational energies lower than the measured values. While the impulsive model predicts higher values, the statistical adiabatic model used here was found to predict values for E-T, E-Vib., E-Rot. according well with the measured experimental values. (C) 2004 Elsevier B.V. All rights reserved.