Journal of Chemical Physics, Vol.101, No.3, 2106-2125, 1994
High-Resolution Crossed Molecular-Beam Investigation of the Absolute Cross-Sections and Product Rotational States for the Reaction F+d-2, (V(I)=0 J(I)=0,1)-)DF(V(F)J(F))+d
High resolution time of flight spectra of DF products have been measured for 12 different center-of-mass angles in the range theta(c.m.)=114 degrees to 180 degrees for the reaction F+D-2-->DF+D at a center-of-mass collision energy of E(c.m.)=82.S+/-2.6 meV. The resolution. is sufficient to clearly resolve the different final product vibrational states and to extract rotational product distributions for each of the vibrational states. Absolute reactive cross sections for the final vibrational states upsilon(f)=1, 2, 3, and 4 were determined from a careful calibration of the beam source intensities and detector sensitivity. For all final vibrational states, nearly the same large rotational surprisal values of ($) over bar theta(R)=5.3 were found. From the rotational distributions, it has also been possible to estimate opacity functions for these final upsilon(f) states via the method of Elsum and Gordon [J. Chem. Phys. 76, 3009 (1982)]. The angular distributions for different upsilon(f) states are compared to recent infinite order sudden approximation (IOSA) and classical trajectory calculations and the general trends with angle are in good agreement. The absolute values of the differential cross sections differ by as much as a factor of 10. The overall reactive cross section is smaller by about a factor of 2 than the most recent classical trajectory calculations, hut the difference is barely within the large experimental errors. These new experiments provide critical data for further improving the parameters of the potential hypersurface.
Keywords:POTENTIAL-ENERGY SURFACE;TRANSITION-STATE;F+H2 REACTION;PHOTOELECTRON-SPECTROSCOPY;SCATTERING CALCULATIONS;QUANTUM;D2;COLLISIONS;F+H2-)HF+H;DEPENDENCE