The photofragmentation of IJKM) = 11 11) state-selected CD31 was performed at 266 nm. The INK) rotational energy level distribution of the resulting vibrationless CD3 photofragment was determined using ( 2 + 1) resonance-enhanced multiphoton ionization. The INK) distribution showed that the dominant mechanism during the dynamics on the excited 3Q0 surface was A K = 0 scattering between the initially excited parent CD31 and the CD3 fragment, i.e., no relative orbital motion about the original C3 axis of the parent, in agreement with previous non-state selected experiments. In addition, smaller but significant amounts of A K = f 3 scattering also occurred. The outline of a model is provided which attributes the effect of nonhelicity conservation and the A K = f 3 propensity to scattering from regions near the conical intersection between the 3 Q~ and 'QI surfaces and in particular to the coupling term between these surfaces. It is therefore suggested that the relative population of the CD3 INK) energy levels for a given N might provide a quantitative measure of the strength of the nonadiabatic coupling between the two surfaces that correlate asymptotically to the 2P3/2 and 2 P~/ 2 spin-orbit energy levels of the atomic iodine photofragment. The experimental INK) rotational distributions are also compared to two recent quantum calculations and are found to be in good agreement for the total scattering into all K levels for a given N . Experimental evidence is also provided, although not analyzed, for the first observation of a detailed photofragmentation differential cross section.

Photoexcitation is used to prepare species whose subsequent fragmentation can be exploited for the purposes of studying, controlling and manipulating different kinds of molecular processes. First, we show how a form of sub-Doppler resolution spectroscopy can be used to determine centre-ofmass kinetic energy distributions, thereby enabling internal energy distributions to be obtained for elementary processes which occur at a fixed total energy. We present data for H atoms monitored at the Lyman-a wavelength. Secondly, we show how such processes can be used to study binary interactions by preparing van der Waals complexes (e.g. C0,HBr

Using combined low-temperature scanning tunneling microscopy and Kelvin probe force microscopy we studied the local electronic structure and work function change of the (0 0 0 1)-oriented epitaxial ZnO layers on a Ag(1 1 1) substrate. Scanning tunneling spectroscopy (STS) revealed that the conduction band minimum monotonically downshifts as the number of the ZnO layers increases up to 4 monolayers (ML). However, it was found by field emission resonance (FER) spectroscopy that the local work function of Ag(1 1 1) slightly decreases for 2 ML thick ZnO but it dramatically changes and drops by about 1.2 eV between 2 and 3 ML, suggesting a structural transformation of the ZnO layer. The spatial variation of the conduction band minimum and the local work function change were visualized at the nanometer scale by mapping the STS and FER intensities. Furthermore, we found that the ZnO layers contained line defects with a few tens of nm long, which can be removed by the injection of a tunneling electron into the conduction band.

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A formalism for the analysis of detailed photofragmentation experiments involving oriented/aligned parent molecules is presented. It is demonstrated for the photofragmentation of an oriented/aligned parent molecule that both the magnitudes and the relative-phases of the transition dipole matrix elements can be determined from angle integrated cross sections or the product orientation/alignment moments derived from them. Formulas are presented for extracting transition dipole matrix elements from the photodissociation of an aligned diatomic molecule to form aligned and/or oriented atomic products using linearly or circularly polarized photolysis lasers. While these detailed measurements are ideally performed using inhomogeneous field state-selected parent molecules, they can be also readily carried out by doing double-resonance photodissociation experiments with polarized lasers. The analysis presented here can, therefore, be used to extract the transition dipole matrix elements from these double-resonance photofragmentation experiments as well.