Vibrational energy distributions of singlet methylene from photolyses of ketene, ketene-d2, diazomethane, and diazomethane-d2 at several wavelengths. A chemically activated methylcyclobutane study

1985 ◽  
Vol 89 (18) ◽  
pp. 3902-3907 ◽  
Author(s):  
W. C. Mahone ◽  
W. Kolln ◽  
J. W. Simons
Keyword(s):  
Vibrational Energy ◽  
Energy Distributions ◽  
Singlet Methylene

Wavelength-dependent photodissociation as a probe for vibrational energy distributions in molecular ions

1996 ◽  
Vol 29 (13) ◽  
pp. 2763-2773 ◽  
Author(s):  
J J Blangé ◽  
X Urbain ◽  
H Rudolph ◽  
H A Dijkerman ◽  
H C W Beijerinck ◽  
...  
Keyword(s):  
Vibrational Energy ◽  
Molecular Ions ◽  
Energy Distributions

SINGLET METHYLENE FROM THERMAL DECOMPOSITION OF DIAZOMETHANE. UNIMOLECULAR REACTIONS OF CHEMICALLY ACTIVATED CYCLOPROPANE AND DIMETHYLCYCLOPROPANE MOLECULES

1962 ◽  
Vol 40 (7) ◽  
pp. 1425-1451 ◽  
Author(s):  
D. W. Setser ◽  
B. S. Rabinovitch
Keyword(s):  
Thermal Decomposition ◽  
Rate Constants ◽  
Vibrational Energy ◽  
Kcal Mole ◽  
Thermal Systems ◽  
Geometric Isomerization ◽  
Wide Range ◽  
Structural Isomerization ◽  
Quantum Statistical ◽  
Singlet Methylene

The thermal decomposition of diazomethane (DM) into singlet methylene radicals and nitrogen has been studied from 225° to 450° in 10:1 olefin–diazomethane mixtures. At 2.5 cm pressure, k = 1.2 × 1012 exp (−34,000/RT) sec−1. The methylene radicals have similar reactivity to methylene generated from photolytic decomposition of DM, as judged by the follow-up reactions with ethylene and cis-butene-2. The structural isomerization reactions of energized cyclopropane and the structural and geometric isomerization of 1,2-dimethyl-cyclopropane (DMC), formed from the addition of the thermally generated methylene to the olefins, were measured from 250° to 450° over a wide range of pressures. For comparison, cyclopropane formed from photolysis at 4358 Å and 25° of DM and ethylene was studied. As judged from comparison of the experimental isomerization rate constants, the energy of the cyclopropanes formed at 350° in the thermal DM system is about the same as for cyclopropanes formed by photolysis at 4358 Å of DM at 25°. The experimental rate constants obtained on the assumption of strong collisions are compared with calculated rate constants which are based on quantum statistical models for kE which fit literature data on conventional thermal isomerization of cyclopropane and DMC. From this comparison, the average energies of the formed molecules in the thermal systems are estimated to be between 107 and 115 kcal/mole, depending upon the temperature. Photolysis at 25° of the ketene–ethylene system (3200 Å) and of DM–ethylene system (4358 Å) give cyclopropane characterized as being at 103 and 111 kcal/mole respectively. These energies deduced from kinetic data are compared with available thermochemical quantities; the existing value of ΔHf0(CH2N2) is questioned. Further support for fast intramolecular relaxation of vibrational energy in DMC, relative to the relaxation process for reaction, is noted. Comparison of data in the literature on the ketene and DM photolytic systems strongly suggests that a larger fraction of the excess light energy resides with methylene from ketene (0.65–0.8) than with methylene from DM (0.3–0.5). Various approximations for the calculation of kE are examined and are compared with accurate quantum statistical evaluation.

Vibrational Energy Transfer in Carbon Monoxide

1972 ◽  
Vol 50 (9) ◽  
pp. 889-897 ◽  
Author(s):  
P. H. Dawson ◽  
W. G. Tam
Keyword(s):  
Energy Exchange ◽  
Vibrational Energy ◽  
Transverse Flow ◽  
Vibration Energy ◽  
Excess Oxygen ◽  
Experimental Measurements ◽  
Energy Distributions ◽  
Vibrationally Excited ◽  
Population Distributions

The role of V–V processes in vibrationally excited CO systems in the longitudinal and transverse flow chemical lasers is studied. Initial vibrational energy distributions of CO formed by the O + CS reaction are deduced from chemiluminescent data using calculated values of the vibration energy exchange probabilities. The time evolution of the population distributions is then obtained by computer simulation. The results are compared with experimental measurements. The effects of excess oxygen and of "cold" CO on the population distributions are also discussed.

Vibrational Energy Distributions of NH2(X̃2B1) Fragments Generated in the Photolysis of NH3at 193 nm:  Application of Kinetic Analysis on Vibrational Cascade

2002 ◽  
Vol 106 (34) ◽  
pp. 7728-7735 ◽  
Author(s):  
Katsuyoshi Yamasaki ◽  
Akihiro Watanabe ◽  
Teruaki Kakuda ◽  
Akira Itakura ◽  
Hirofumi Fukushima ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Vibrational Energy ◽  
Energy Distributions ◽  
193 Nm

Initial vibrational energy distributions determined by infra-red chemiluminescence

1971 ◽  
Vol 20 (1) ◽  
pp. 93-102 ◽  
Author(s):  
Neville Jonathan ◽  
C.M. Melliar-Smith ◽  
David H. Slater
Keyword(s):  
Vibrational Energy ◽  
Energy Distributions ◽  
Infra Red
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