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Freon123 (CF3CHC12 and CF3CDC12) molecules are superexited by the intense IR laser pulse without tail from the TEA CO2 laser, reaching very high exited state. In the dissociation processes, it is shown that the C-C bonds having higher energy in Freon123 were mostly broken under certain experimental conditions, but only a few C-Cl bonds having lowest energy ruptured. The main products were C2F6, and H2C=C=CH2 and it's substitution derivatives. It is indicated by the relationship between the relative yields of productions and laser energy flux that intramolecular V-V energy transfer of Freon123 is nonrandomizational.

Freon 113 molecules are superexited in multifrequency intense IR laser fields composed of 9P(24), 9P(22), 9P(20), 9P(18) lines of TEA CO2 laser, reaching very high exited states. It can be seen from the decomposition curve that a "siphonage effect" exists obviously in the V-V energy transfer between CF2C1·CFC12 and CF3·CCl3 molecules. From the main products C2F6, C2Cl6, C2F4 and C2F2C12, it is shown that the C-C bonds having higher energy in CF2Cl·CFCl2 and CF3·CCl3 were mostly broken, but only a few C-Cl bands having lowest energy ruptured. We propose a dissociation mechanism of Freon 113 molecule in multifrequency intense IR fields, and indicate that intramolecular V-V energy transfer is not randomized.

Electronically excited radicals C 2 * were formed from CHC1F 2 molecules by irradiation with a TEA CO 2 laser. Six bands of Swan system have been observed. The mechanism of the formation of C 2 * d 3 Π g state in the infrared multiphoton dissociation of CHC1F 2 is presented based on the potential energy curves of the C 2 molecule. C 2 is a somewhat unnsual molecule, the state b 3 ∑ g - crosses the first excited state a 3 Π u at an internuclear distance of about 1.80?, and lies below it for greater nuclear separations. At first, the state b 3 ∑ g - is formed in the elementary step C + CF 2 + M→C 2 * + F 2 + M of the reactionsof the photoproducts of CHC1F 2 in preference to the low-lying X 1 ∑ g + and a 3 Π u states, and then undergoes a radiationless transition into the d 3 Π g state through crossing with the d 3 Π g ,ν′= 6 level.

The optothermal spectrum of infrared MPA of CF3CDC12 obtained by using optothermal cell with a platinum filament as a detector is reported here. It is found that the absorption peak at 944 cm-1 in infrared linear absorption spectrum splits into two peaks at 947 cm-1 and 927cm-1 in MPA spectrum. This phenomenon could be related to-the coupling of normal vibrations produced by Coriolis forces and anharmonisity. So one could select a more suitable excited wavelength according to this new result in laser separation of deuterium isotop. The absoption peak at 986 cm-1 in infrared linear absorption spectrum shows a red shift of 6cm-1 in MPA spectrum. This is due to the anhamonicity of vibrational levels of the molecule.