Average CO vibrational energies

Table I. Average CO Vibrational Energies and Absolute Rate Constants for CO Production at 300K for 0(3P) + 1-Alkynes.

Exothermicities and average CO vibrational energies (in units of kcal/mole) were computed by assuming that the reactions involve triplet CH2, except with C02 which is reactive only with excited singlet CH2 (see the text). 

The results of simple statistical calculations based on the RRK and RRKM theories of unimolecular reactions agree well with the observed vibrational population distribution. At 293 K, the computed average CO vibrational energy is 9.8 kcal/mole according to RRK and 10.2 according to RRKM calculations. Both agree quantitatively with the experimental value, 9.9 0.5. 

Average CO vibrational energy in kcal/mole. Statistically expected values. 

Generally, good agreement was found between the experimentally observed and the statistically predicted population distributions assuming diradicals (as shown above) are formed initially instead of their alkene isomers. Table I summarizes results which show the comparison between the experimentally determined average product CO vibrational energies and the statistically expected values. 

The photolysis of CH2CO at 193 nm has also been studied by Fujimoto et al. (50). A CO laser was used to probe the vibrational excitation of the CO produced. The product CO contains an average vibrational energy of 6.4 kcal/mol. The vibrational population distribution corresponds to about 4000 K in good agreement with Sonobe and Rosenfeld (49,50). 

Table II. Average CO Product Vibrational Energies Measured for the Reactions of CH2 with 0(3P), 02 and C02...

Spectroscopic constants of the X1 + state of CO molecule obtained by vibrational averaged over potential energy curve calculated by MCSCF method. 

As another example consider the internal vibrational energy of a diatomic solute molecule, for example, CO, in a simple atomic solvent (e.g. Ar). This energy can be monitored by spectroscopic methods, and we can follow processes such as thermal (or optical) excitation and relaxation, energy transfer, and energy migration. The observable of interest may be the time evolution of the average... 

Average Vibrational Energy of the CO Formed in Some 0( P) +Alkyne/Allene and Some Photodissociation Reactions... 

Experiments were also carried out using isotopically labeled 0 atoms. Under these conditions, the C 0 laser probe cannot detect the C 0 produced by the attack on the center C atom, the entire CO absorption signal is due to the C 0 formed from the already present in the CjOj molecule. The C 0 vibrational distribution thus obtained is also shown in Fig. 20, and is noticeably colder than that produced by the unlabeled O atoms. This impUes that vibrationally hotter CO is produced from the center C atom. The deconvolution of these data showed that the average vibrational energy carried by CO from the center C atom amounted to about 15 kcal/mole, compared with only about 4 kcal/mole for the two CO s derived from the C = 0 bonds initially present in the C3O2. 

Hall et al. (1995) studied the infrared emission from CO and C2H5 formed in the photolysis of 3-pentanone at 193 nm. The process (II) occurs with formation of CO with a rotational temperature of 2,100 K and an average vibrational energy in the range... 

The angular-dependent adiabatic potential energy curves of these complexes obtained by averaging over the intermolecular distance coordinate at each orientation and the corresponding probability distributions for the bound intermolecular vibrational levels calculated by McCoy and co-workers provide valuable insights into the geometries of the complexes associated with the observed transitions. The He - - IC1(X, v" = 0) and He + 1C1(B, v = 3) adiabatic potentials are shown in Fig. 3 [39]. The abscissa represents the angle, 9,... 

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