Reactive scattering dynamics in atom+polyatomic systems: F+C2H6→HF(v,J)+C2H5

Whitney, Erin S.; Zolot, Alexander M.; McCoy, Anne B.; Francisco, Joseph S.; Nesbitt, David J.
March 2005
Journal of Chemical Physics;3/22/2005, Vol. 122 Issue 12, p124310
Academic Journal
State-to-state scattering dynamics of F+C2H6→HF(v,J)+C2H5 have been investigated at Ecom=3.2(6) kcal/mol under single-collision conditions, via detection of nascent rovibrationally resolved HF(v,J) product states with high-resolution infrared laser absorption methods. State-resolved Doppler absorption profiles are recorded for multiple HF(v,J) transitions originating in the v=0,1,2,3 manifold, analyzed to yield absolute column-integrated densities via known HF transition moments, and converted into nascent probabilities via density-to-flux analysis. The spectral resolution of the probe laser also permits Doppler study of translational energy release into quantum-state-resolved HF fragments, which reveals a remarkable linear correlation between (i) HF(v,J) translational recoil and (ii) the remaining energy available, Eavail=Etot-EHF(v,J). The dynamics are interpreted in the context of a simple impulsive model based on conservation of linear/angular momentum that yields predictions in good agreement with experiment. Deviations from the model indicate only minor excitation of ethyl vibrations, in contrast with a picture of extensive intramolecular vibrational energy flow but consistent with Franck–Condon excitation of the methylene CH2 bending mode. The results suggest a relatively simple dynamical picture for exothermic atom+polyatomic scattering, i.e., that of early barrier dynamics in atom+diatom systems but modified by impulsive recoil coupling at the transition state between translational/rotational degrees of freedom.


Related Articles

  • Mechanisms of optical angular momentum transfer to nematic liquid crystalline droplets. Wood, Tiffany A.; Gleeson, Helen F.; Dickinson, Mark R.; Wright, Amanda J. // Applied Physics Letters;5/24/2004, Vol. 84 Issue 21, p4292 

    A detailed study is presented that evaluates the relative importance of wave plate behavior, scattering processes and absorption phenomena in transferring optical torque from circularly polarized light to optically trapped nematic droplets. A wide range of parameters is considered: droplet...

  • Bessel beam does a twist. Marx, Bridget // Laser Focus World;Sep2003, Vol. 39 Issue 9, p24 

    Reports that in certain optical conditions, light beams can transfer angular momentum to trapped particles. Use of light to grab and hold minute objects in place.

  • Quadrature-based, coarse-grained treatment of the coordinate representation free particle real-time evolution operator. Sharafeddin, Omar A.; Kouri, Donald J.; Nayar, Naresh; Hoffman, David K. // Journal of Chemical Physics;9/1/1991, Vol. 95 Issue 5, p3224 

    In this paper we report a quadrature evaluation of the coordinate representation, short-time free particle propagator, 〈R|exp(-iH0τ)|R’>. The result is the elimination of most of the highly oscillatory behavior in this quantity yielding in its stead a much smoother function,...

  • Benchmark calculations of thermal reaction rates. I. Quantal scattering theory. Chatfield, David C.; Truhlar, Donald G.; Schwenke, David W. // Journal of Chemical Physics;2/1/1991, Vol. 94 Issue 3, p2040 

    The thermal rate coefficient for the prototype reaction H+H2→H2+H with zero total angular momentum is calculated by summing, averaging, and numerically integrating state-to-state reaction probabilities calculated by time-independent quantum-mechanical scattering theory. The results are...

  • Two-Photon Bremsstrahlung Processes in Atoms: Polarization Effects and Analytic Results for Coulomb Potential. Krylovetskiı, A. A.; Manakov, N. L.; Marmo, S. I.; Starace, A. F. // Journal of Experimental & Theoretical Physics;Dec2002, Vol. 95 Issue 6, p1006 

    The partial wave analysis of two-photon free–free (bremsstrahlung) electron transition cross sections during scattering by a static potential U(r), as well as by an atom with a nonzero angular momentum, is carried out. The dipole interaction with radiation is taken into account in the...

  • A classical trajectory study of inelastic scattering of NO from graphite surfaces: Rotational energy distributions. Pettersson, Jan B. C.; Nyman, Gunnar; Holmlid, Leif // Journal of Chemical Physics;12/1/1988, Vol. 89 Issue 11, p6963 

    The inelastic scattering of NO molecules from graphite surfaces is studied by classical trajectory methods. The experimental results from Frenkel et al. (1982), Segner et al. (1983), and Häger and Walther (1984) are analyzed. A model using a small isolated part of the graphite surface in...

  • Photofragment angular momentum distribution beyond the axial recoil approximation: The role of molecular axis rotation. Kuznetsov, Vladislav V.; Vasyutinskii, Oleg S. // Journal of Chemical Physics;7/15/2005, Vol. 123 Issue 3, p034307 

    We present the quantum-mechanical expressions for the recoil angle dependence of the photofragment multipole moments which explicitly treat the role of molecular axis rotation on the electronic angular momentum polarization of the fragments. The paper generalizes the result of Siebbeles et al....

  • Laser spectroscopy of NiO: The 3Σ- ground state. Srdanov, Vojislav I.; Harris, David O. // Journal of Chemical Physics;9/1/1988, Vol. 89 Issue 5, p2748 

    The results of the first rotational analysis of NiO are reported. Several bands in the green spectra region were resolved and analyzed using laser induced fluorescence (LIF). It was found that the symmetry of the well behaved ground electronic state is 3Σ- as was predicted by ab initio...

  • Autler–Townes splitting and the AC Stark effect in nonpolar molecules: Prospects for all-optical alignment. Marjatta Lyyra, A.; Jianbing Qi; Spano, Frank C. // Canadian Journal of Physics;Feb2001, Vol. 79 Issue 2, p547 

    This paper describes an extension of the familiar coherence effects from atomic systems to the molecular regime. Such effects are inherent in the interaction of multiple laser fields with molecular systems. We have observed Autler–Townes splitting and the AC Stark shift in diatomic...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics