EMISSION SPECTROSCOPY OF THE PREDISSOCIATIVE EXCITED STATE DYNAMICS OF ACROLEIN, ACRYLIC ACID, AND ACRYLOYL CHLORIDE AT 199 NM

摘要

The emission spectroscopy of acrolein (C3H4O), acrylic acid (C2H3COOH), and acryloyl chloride (C2H3COCl) excited at 199 nm elucidates the dominant electronic character of the excited state reached by the optical transition at this wavelength. Progressions in the C=C and C=O stretching overtones and various combination bands suggest the antibonding orbital has mixed pi(*)(C=C)/pi(*)(C=O) character. We interpret the results in conjunction with ab initio calculations at the configuration interaction singles level to identify the influence of resonance in the excited state of these conjugated molecules. The results on acrylic acid are of particular interest as excitation in this absorption band produces the HOCO intermediate of the OH+CO-->H+CO2 reaction that is important in combustion. (C) 1995 American Institute of Physics. [References: 25]