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The reaction H+CD4→CHD3+D is shown to take place by an inversion mechanism. The evidence is as follows. When the H atom has an anisotropic (perpendicular) velocity distribution, the D atom velocity distribution is also perpendicular. For a relative energy near 2 eV, the reaction cross section for H+CD4 is 0.084±0.014 A2 and for H+CH3D is 0.040±0.015 A2. At the same H atom energy, when CH3CD3 is substituted for CD4, no D atoms can be detected. Finally, around 80% of the initial H atom kinetic energy is released as kinetic energy of the D atom showing that the reaction is nearly vibrationally adiabatic. [ABSTRACT FROM AUTHOR]

The H, D, and Cl atoms from the photodissociation of HCl and DCl at 157 and 193 nm were detected by laser-induced fluorescence (LIF) in the vacuum ultraviolet region. The Doppler profiles of the H and D resonance lines at 121.6 nm in the LIF spectra indicate that the absorption of HCl and DCl at 157 nm is a mixture of perpendicular and parallel transition (A 1Π, a 3Π0+←X 1Σ+), while that at 193 nm results almost solely from the A 1Π←X 1Σ+ transition. The fine-structure branching ratios, are measured for the chlorine atom by LIF. Combined with the previous results, the branching ratios [Cl*(2P1/2)]/[Cl(2P3/2)] are 0.81±0.09 at 157 nm, 0.50±0.05 at 193 nm for HCl, and 0.23±0.05 at 193 nm for DCl. These results suggest that the nonadiabatic couplings during the breakup of HCl (DCl) in the excited states play an important role in determination of the fine-structure branching ratios. [ABSTRACT FROM AUTHOR]

The Doppler profiles of the O(1D) products from the photodissociation of O2 at 157.6 nm and NO2 and N2O at 205.47 nm are detected by a resonance enhanced multiphoton ionization technique. The translation energy and angular distributions are deduced for the O(1D) atoms. Present results indicate that (a) O2 (B 3Σ-u) has a short dissociative lifetime when irradiated at 157.6 nm, (b) NO(2Π) photofragment from NO2 at 205.47 nm is mostly vibrationally excited, and (c) most of the available energy is released as kinetic energy when N2O is photodissociated at 205.47 nm. [ABSTRACT FROM AUTHOR]