Time Evolution of :CF2 in the IR Multiphoton Dissociation of CF2Cl2: RRKM Considerations

The CO2 laser induced multiphoton dissociation of CF2Cl2 takes place in atomic and molecular chlorine elimination channels, with about 8% of the reaction by the latter channel. Time resolved experiments show a fast formation of :CF2 from the primary reaction, followed by a secondary slow growth from the decomposition of CF2Cl. The experimental rates are consistent with the RRKM rate constants with an excitation energy of nearly 343 kJ/mol in CF2Cl2. At high laser fluences, addition of argon has improved the dissociation yield, due to rotational hole filling mechanism. The internal energy of CF2Cl2 decreases from 356 to 343 kj/mol on addition of argon as buffer gas. The nascent vibrational temperature of the CF2 is 950 K, whereas an overall temperature of the thermalized ensemble in milliseconds time is computed to be 480 K.