Photodissociation of HCl at 193.3 nm: Spin–orbit branching ratio

Zhang, J.; Dulligan, M.; Wittig, C.

doi:10.1063/1.474494

Cited by 71 publications

(62 citation statements)

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“…This ratio differs considerably from that found by Matsumi et al [17], 0.25 AE 0.05 and by Tiemann et al [7], 0.33 AE 0.03, in the 193 photodissociation of vibrationless ground state CH 2 Cl 2 . This is so, even if the Cl Ã /Cl ratio of Matsumi et al [17], is corrected to 0.34 AE 0.07 after the new value of the two-photon oscillator strength ratio for the corresponding REMPI transitions is considered [33]. Since the combined energy used in the VMP of CH 2 Cl 2 , $51 180 cm À1 , is only slightly less than that used in the 193 nm photodissociation, 51 813 cm À1 , it seems unreasonable that the difference in energy led to the variation in the branching ratio.…”

Section: Resultsmentioning

confidence: 99%

Photodissociation dynamics of vibrationally excited CH2Cl2 molecules

Marom

Golan

Rosenwaks

et al. 2003

Chemical Physics Letters

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Section: Resultsmentioning

confidence: 99%

Photodissociation dynamics of vibrationally excited CH2Cl2 molecules

Marom

Golan

Rosenwaks

et al. 2003

Chemical Physics Letters

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“…The relative strengths of the initial LIF signals in Figure 4 have been scaled to reproduce the 0.59:0.41 ratio of Cl and Cl* formation from HCl photolysis at 193 nm. 24 To quantify the relative importance of reactions 1-4, expressions 7 and 8 were evaluated and compared to the observed Cl and Cl* profiles.…”

Section: Reaction and Relaxation Of Cl*( 2 P 1/2 ) In Collisions Withmentioning

confidence: 99%

Kinetics of the Reactions of Cl*(²P_1/2) and Cl(²P_3/2) Atoms with CH₃OH, C₂H₅OH, n-C₃H₇OH, and i-C₃H₇OH at 295 K

et al. 2005

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The title reactions were studied using laser flash photolysis/laser-induced-fluorescence (FP-LIF) techniques. The two spin-orbit states, Cl*(2P(1/2)) and Cl(2P(3/2)), were detected using LIF at 135.2 and 134.7 nm, respectively. Measured reaction rate constants were as follows (units of cm3 molecule(-1) s(-1)): k(Cl(2P(3/2))+CH3OH) = (5.35 +/- 0.24) x 10(-11), k(Cl(2P(3/2))+C2H5OH) = (9.50 +/- 0.85) x 10(-11), k(Cl(2P(3/2))+n-C3H7OH) = (1.71 +/- 0.11) x 10(-10), and k(Cl(2P(3/2))+i-C3H7OH) = (9.11 +/- 0.60) x 10(-11). Measured rate constants for total removal of Cl*(2P(1/2)) in collisions with CH3OH, C2H5OH, n-C3H7OH, and i-C3H7OH were (1.95 +/- 0.13) x 10(-10), (2.48 +/- 0.18) x 10(-10), (3.13 +/- 0.18) x 10(-10), and (2.84 +/- 0.16) x 10(-10), respectively; quoted errors are two-standard deviations. Although spin-orbit excited Cl*(2P(1/2)) atoms have 2.52 kcal/mol more energy than Cl(2P(3/2)), the rates of chemical reaction of Cl*(2P(1/2)) with CH3OH, C2H5OH, n-C3H7OH, and i-C3H7OH are only 60-90% of the corresponding Cl(2P(3/2)) atom reactions. Under ambient conditions spin-orbit excited Cl* atoms are responsible for 0.5%, 0.5%, 0.4%, and 0.7% of the observed reactivity of thermalized Cl atoms toward CH3OH, C2H5OH, n-C3H7OH, and i-C3H7OH, respectively.

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“…Although there is still a controversy, the branching ratio ͓Cl( 2 P 1/2 )͔/͓Cl( 2 P 3/2 )͔ appears to be rather high, not far from unity for some excitation wavelengths. [25][26][27][28][29] An exact description of the Ar-HCl photodissociation dynamics including several nonadiabatically coupled electronic states becomes prohibitively expensive. However, some of the effects of including several electronic states on the calculated product distributions can be qualitatively predicted.…”

Section: Theoretical Treatmentmentioning

confidence: 99%

Photodissociation of Ar–HCl: An energy-resolved study of the dynamics of total fragmentation into H+Ar+Cl

Juanes‐Marcos

Garcı́a-Vela

1999

The Journal of Chemical Physics

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UV photolysis of Ar-HCl is simulated by means of an exact wave packet treatment in three dimensions. The focus of the work is on the mechanism of indirect dissociation of the hydrogen atom, which leads to total fragmentation of Ar-HCl into H, Ar, and Cl. The results predict for this photodissociation path a probability of about 13% of the photolysis process. The remaining probability would be associated with direct photodissociation of the H fragment. Kinetic-energy distributions of the hydrogen fragments produced by indirect photodissociation are calculated for different excitation energies of Ar-HCl. The distributions reflect a pronounced structure of peaks associated with broad and overlapping resonances of the system. The resonance structure is present in the whole energy range covered by the absorption spectrum. Hydrogen atoms initially populating the resonances can dissociate from the cluster extensively cooled down, after several collisions with Ar and Cl. A mechanism is suggested for the fragmentation process due to indirect photodissociation, which involves successive jumps of the hydrogen to lower-energy resonances, induced by the collisions. A classical collisional model is proposed to rationalize qualitatively the fragmentation dynamics.

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Photodissociation of HCl at 193.3 nm: Spin–orbit branching ratio

Abstract: Photodissociation of alkyl and aryl iodides and effect of fluorination: Analysis of proposed mechanisms and vertical excitations by spin-orbit ab initio study

Cited by 71 publications

References 20 publications

Photodissociation dynamics of vibrationally excited CH2Cl2 molecules

Photodissociation dynamics of vibrationally excited CH2Cl2 molecules

Kinetics of the Reactions of Cl*(²P_1/2) and Cl(²P_3/2) Atoms with CH₃OH, C₂H₅OH, n-C₃H₇OH, and i-C₃H₇OH at 295 K

Photodissociation of Ar–HCl: An energy-resolved study of the dynamics of total fragmentation into H+Ar+Cl

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Photodissociation of HCl at 193.3 nm: Spin–orbit branching ratio

Abstract: Photodissociation of alkyl and aryl iodides and effect of fluorination: Analysis of proposed mechanisms and vertical excitations by spin-orbit ab initio study

Cited by 71 publications

References 20 publications

Photodissociation dynamics of vibrationally excited CH2Cl2 molecules

Photodissociation dynamics of vibrationally excited CH2Cl2 molecules

Kinetics of the Reactions of Cl*(2P1/2) and Cl(2P3/2) Atoms with CH3OH, C2H5OH, n-C3H7OH, and i-C3H7OH at 295 K

Photodissociation of Ar–HCl: An energy-resolved study of the dynamics of total fragmentation into H+Ar+Cl

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Kinetics of the Reactions of Cl*(²P_1/2) and Cl(²P_3/2) Atoms with CH₃OH, C₂H₅OH, n-C₃H₇OH, and i-C₃H₇OH at 295 K