Thermochemistry of Haloethanes

Kolesov, V.P.; Papina, T. S.

doi:10.1070/rc1983v052n05abeh002829

Cited by 44 publications

(40 citation statements)

References 8 publications

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“…where E avl is the available energy, E hn is the photon energy, D 0 = 294 kJ mol À1 [30] is the bond dissociation energy of CÀBr, E el is the electronic energy level of the bromine atom, which is equal to 0 kJ mol À1 for Br and 44 kJ mol À1 for Br*, E int is the internal energy of the parent molecules, which is estimated to be zero since the rotational and vibrational excitations are negligible in a supersonic molecular beam, and f T represents the fractions of the translational energies. Herein, the photodissociation of C 2 H 5 Br has been studied in the wavelength range of 231-267 nm, and all the dynamic properties at these wavelengths are listed in Table 1.…”

Section: Speed and Angular Distributionmentioning

confidence: 99%

Photodissociation Study of Ethyl Bromide in the Ultraviolet Range by the Ion‐Velocity Imaging Technique

Tang¹,

Ji²,

Zhu³

et al. 2005

ChemPhysChem

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The photodissociation of ethyl bromide has been studied in the wavelength range of 231-267 nm by means of the ion velocity imaging technique coupled with a [2+1] resonance-enhanced multiphoton ionization (REMPI) scheme. The velocity distributions for the Br ((2)P(1/2)) (denoted Br*) and Br ((2)P(3/2)) (denoted Br) fragments are determined, and each can be well-fitted by a narrow single-peaked Gaussian curve, which suggests that the bromine fragments are generated as a result of direct dissociation via repulsive potential-energy surfaces (PES). The recoil anisotropy results show that beta(Br) and beta(Br*) decrease with the wavelength, and the angular distributions of Br* suggest a typical parallel transition. The product relative quantum yields at two different wavelengths are Phi(234nm)(Br*)=0.17 and Phi(267nm)(Br*)=0.31. The relative fractions of each potential surface for the bromine fragments' production at 234 and 267 nm reveal the existence of a curve crossing between the (3)Q(0) and (1)Q(1) potential surfaces, and the probability of curve crossing decreases with the laser wavelength. The symmetry reduction of C(2)H(5)Br from C(3v) to C(s) invokes a nonadiabatic coupling between the (3)Q(0) and (1)Q(1) states, and with higher energy photons, the probability that crossing will take place increases.

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Section: Speed and Angular Distributionmentioning

confidence: 99%

Photodissociation Study of Ethyl Bromide in the Ultraviolet Range by the Ion‐Velocity Imaging Technique

Tang¹,

Ji²,

Zhu³

et al. 2005

ChemPhysChem

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“…For the two first groups we have used the values (−676.5 kJ·mol −1 ) and (−409.9 kJ·mol −1 ) from reference 15 in which 23 group values have been generated for estimating the enthalpies of formation of organic halogen compounds. The value (−395.0 kJ·mol −1 ) for the third group was evaluated by dividing D f H°m(g) (298.15 K) (16) by two for CF 2 BrCF 2 Br, which was obtained by recalculating the original data of Lacher et al (17) The values of absolute entropy of C(cr, graphite), F 2 (g) and Br 2 (1) were taken from Cox et al (18) The Gibbs free energies of formation and the enthalpies of formation of 1-bromoperfluorooctane in the gas and liquid states are given in table 6.…”

Section: Resultsmentioning

confidence: 99%

Low-temperature heat capacity of 1-bromoperfluorooctane

Varushchenko

Дружинина

Sorkin

1997

The Journal of Chemical Thermodynamics

339

106

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“…dCalculated using the same procedure as in h (this work) from K776 = 0.8 measured by Puyo et al [27,28]. 'Calculated by Kolesov and Papina [29] from K776 = 0.8 [27,28], using the "third law method." 'Calculated by Kolesov and Papina [29] which tits the pyrolyses of CClj and C2C16 under rather extreme experimental conditions.…”

Section: Pyrolysis Of Cci4mentioning

confidence: 99%

“…'Calculated by Kolesov and Papina [29] from K776 = 0.8 [27,28], using the "third law method." 'Calculated by Kolesov and Papina [29] which tits the pyrolyses of CClj and C2C16 under rather extreme experimental conditions. Moreover the ability of computer aided design of new experiments which may further elucidate the mechanism has also been demonstrated.…”

Section: Pyrolysis Of Cci4mentioning

confidence: 99%

The pyrolysis of CCl4 and C2Cl6 in the gas phase. Mechanistic modeling by thermodynamic and kinetic parameter estimation

Huybrechts

Narmon

Mele

1996

Int. J. Chem. Kinet.

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A detailed radical reaction mechanism is proposed to describe the thermal reactions of CCl4 and C2Cl6 in the gas phase quantitatively. A consistent set of activation energies and preexponential factors for all elementary reactions, in combination with enthalpies of formation and entropies for all species involved, is computer optimized to fit experimental pressure‐rise curves and concentration profiles. For this purpose new experimental results on the pyrolysis of CCl4 are used, together with published kinetic data on the pyrolysis of C2Cl6 (in the absence and in the presence of Cl2). © 1996 John Wiley & Sons, Inc.

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Thermochemistry of Haloethanes

Cited by 44 publications

References 8 publications

Photodissociation Study of Ethyl Bromide in the Ultraviolet Range by the Ion‐Velocity Imaging Technique

Photodissociation Study of Ethyl Bromide in the Ultraviolet Range by the Ion‐Velocity Imaging Technique

Low-temperature heat capacity of 1-bromoperfluorooctane

The pyrolysis of CCl4 and C2Cl6 in the gas phase. Mechanistic modeling by thermodynamic and kinetic parameter estimation

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