Rotational excitation of oriented molecules as a probe of molecule-surface interaction

Dynamical steering in an electron transfer surface reaction: Oriented NO(v = 3, 0.08 < Ei < 0.89 eV) relaxation in collisions with a Au(111) surface

“…A similar rotational rainbow has been observed in scattering experiments of vibrationally ground state NO molecules from a Ag(111) surface. 1 In our work, we can clearly see that the rotational rainbow observed in the vibrationally elastic channel is strongly enhanced for O-atom first collisions, but still present for N-atom first orientation (blue curve in panels (a)-(e)). This shows that the rotational rainbow occurring for randomly oriented NO molecules (green curve) is dominated by O-atom first collisions.…”

“…[1][2][3][4][5][6] Experiments with adsorbed molecules also reveal strong orientational influences, for example, surface aligned photochemistry. [7][8][9] This raises an important question: When oriented molecules approach a surface adsorption site, to what extent does the growing interaction with the surface re-orient the molecule either away from or towards a favorable reactive geometry?…”

Angular dependence of rotational and vibrational energies of product CO2 in CO oxidation on Pd(110)

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] However, angle-resolved (AR) measurements [6][7][8][9][10][11][12] of internal energies have long been lacking in thermal surface reactions because of the difficulty in conducting such experiments, 18 although such measurements are required in order to obtain detailed structural information. In this paper, results of measurements of internal energies of AR product CO 2 in CO oxidation on Pd (110) are presented.…”

Orientation and energy dependence of NO scattering from Pt(111)

“…27,28 The rotational excitation can be modeled by a sudden excitation on the repulsive wall of the PES and the maximum of the derivative of the potential with respect to the orientation angle of the molecule gives rise to a maximum in the rotational excitation, which has been assigned as a rotational rainbow. 2,27,28 These rainbows manifest themselves in a nonBoltzmann behavior of the rotational energy distribution. Quantum and classical calculations have further shown that surface recoil is significant in such experiments and modifies the rainbow positions.…”

“…For spectroscopic reasons, such experiments are particularly well suited to the NO molecule. [2][3][4][5][6][7][8][9][10][11][12][13] The measured features resulting from the scattering experiments cannot directly be linked to the potential energy surface. Molecular dynamics ͑MD͒ simulations can give insight how those features are connected to properties of the potential energy surface and provide detailed information on the dynamical processes of the gas-surface interaction.…”