State-specific neutral time-of-flight of CO from ketene photodissociation at 351 nm: The internal energy distribution of CH2 X3B1
Metastable lime-of-flight (TOF) spectroscopy was used to measure the translational energy distribution of specific rotational states of CO formed from ketene photodissociation (CH2CO-->CH2+CO) at 351 nm. This distribution could be directly related to the internal energy distribution of the other fragment ((X) over tilde B-3(1) CH2) formed in the reaction, thereby giving a correlated distribution of the internal states of the fragments. This technique overcomes the spectral complexity associated with detection the <(X)over tilde B-3(1)> state CH2. Previous measurements of the CO rotational distribution were simulated theoretically using the impulsive model and zero-point vibrational energy considerations. These models predicted that the rotational distributions of CO and CH2 should be uncorrelated, that similar to 10% of the CH2 should be vibrationally excited with one quantum in the bending mode, and that the rotational energy distribution of CH2 should peak near zero. Measurements presented in this paper show a slight anticorrelation of CO and CH2 rotations, no vibrational excitation of CH2 and Gaussian-like rotational energy distributions of CH2 that peak at similar to 1 kcal/mole and have a full width at half-maximum of similar to 0.8 kcal/mol. Qualitative explanations for this behavior are presented.
Record created on 2011-05-11, modified on 2016-08-09