Insensitivity of trapping at surfaces to molecular vibration

We have measured the trapping probability of NO(v = 0 and v = 2) on Au(1 1 1) as a function of translational energy of incidence. The range of translational and vibrational energies probed is comparable, yet the influence of the two types of motion is very different; 0.46 eV of translational energy is sufficient to completely suppress trapping, but the 0.46 eV of vibrational energy in NO(v = 2) has no measurable effect. The insensitivity of trapping probabilities to vibrational energy stands in sharp contrast to the strong sensitivity of direct activated dissociative adsorption to vibrational energy.