Abstract
We show that quantum-specific detection of DIET processes of polyatomic adsorbates reveals the multidimensional dynamics of intramolecular motion. Specifically, we present an analysis of the 6-350 eV electron-induced desorption and dissociation of chemisorbed NH3 and ND3 on Pt(1 1 1). State-selective detection of the neutral DIET products is accomplished by 2 + 1 resonance-enhanced multiphoton ionization (REMPI). Desorption and dissociation occur as a result of distinct electronic excitations that result in different, uncoupled, modes of intramolecular motion. We find that desorption results from 3a1 -1-induced inversion motion. Trajectories on a two-dimensional potential energy surface reveal that the excited molecule fully inverts; upon deexcitation, the inverted molecule is sufficiently high on the hard wall of the substrate interaction to have enough energy to desorb. Given the short excitation lifetime, the time scale in which the (H) D atoms reach the inversion geometry directly affects the desorption yield and results in an appreciable enhancement of NH3 desorption over that of ND3. In general, multidimensional molecule-surface potential energy surfaces should be considered in DIET processes involving molecular adsorbates.
| Original language | English |
|---|---|
| Pages (from-to) | 41-48 |
| Number of pages | 8 |
| Journal | Nuclear Inst. and Methods in Physics Research, B |
| Volume | 101 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - Jun 3 1995 |
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ASJC Scopus subject areas
- Instrumentation
- Nuclear and High Energy Physics
Cite this
Intramolecular motion in DIET : desorption and dissociation of chemisorbed ammonia. / Burns, A. R.; Stechel, Ellen; Jennison, D. R.
In: Nuclear Inst. and Methods in Physics Research, B, Vol. 101, No. 1-2, 03.06.1995, p. 41-48.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Intramolecular motion in DIET
T2 - desorption and dissociation of chemisorbed ammonia
AU - Burns, A. R.
AU - Stechel, Ellen
AU - Jennison, D. R.
PY - 1995/6/3
Y1 - 1995/6/3
N2 - We show that quantum-specific detection of DIET processes of polyatomic adsorbates reveals the multidimensional dynamics of intramolecular motion. Specifically, we present an analysis of the 6-350 eV electron-induced desorption and dissociation of chemisorbed NH3 and ND3 on Pt(1 1 1). State-selective detection of the neutral DIET products is accomplished by 2 + 1 resonance-enhanced multiphoton ionization (REMPI). Desorption and dissociation occur as a result of distinct electronic excitations that result in different, uncoupled, modes of intramolecular motion. We find that desorption results from 3a1 -1-induced inversion motion. Trajectories on a two-dimensional potential energy surface reveal that the excited molecule fully inverts; upon deexcitation, the inverted molecule is sufficiently high on the hard wall of the substrate interaction to have enough energy to desorb. Given the short excitation lifetime, the time scale in which the (H) D atoms reach the inversion geometry directly affects the desorption yield and results in an appreciable enhancement of NH3 desorption over that of ND3. In general, multidimensional molecule-surface potential energy surfaces should be considered in DIET processes involving molecular adsorbates.
AB - We show that quantum-specific detection of DIET processes of polyatomic adsorbates reveals the multidimensional dynamics of intramolecular motion. Specifically, we present an analysis of the 6-350 eV electron-induced desorption and dissociation of chemisorbed NH3 and ND3 on Pt(1 1 1). State-selective detection of the neutral DIET products is accomplished by 2 + 1 resonance-enhanced multiphoton ionization (REMPI). Desorption and dissociation occur as a result of distinct electronic excitations that result in different, uncoupled, modes of intramolecular motion. We find that desorption results from 3a1 -1-induced inversion motion. Trajectories on a two-dimensional potential energy surface reveal that the excited molecule fully inverts; upon deexcitation, the inverted molecule is sufficiently high on the hard wall of the substrate interaction to have enough energy to desorb. Given the short excitation lifetime, the time scale in which the (H) D atoms reach the inversion geometry directly affects the desorption yield and results in an appreciable enhancement of NH3 desorption over that of ND3. In general, multidimensional molecule-surface potential energy surfaces should be considered in DIET processes involving molecular adsorbates.
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U2 - 10.1016/0168-583X(95)00053-4
DO - 10.1016/0168-583X(95)00053-4
M3 - Article
VL - 101
SP - 41
EP - 48
JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
SN - 0168-583X
IS - 1-2
ER -