Intramolecular motion in DIET: desorption and dissociation of chemisorbed ammonia

A. R. Burns, Ellen Stechel, D. R. Jennison

Research output: Contribution to journalArticle

7 Citations (Scopus)

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 languageEnglish
Pages (from-to)41-48
Number of pages8
JournalNuclear Inst. and Methods in Physics Research, B
Volume101
Issue number1-2
DOIs
Publication statusPublished - Jun 3 1995

Fingerprint

ammonia
Ammonia
Desorption
desorption
dissociation
Potential energy surfaces
Adsorbates
Molecules
uncoupled modes
potential energy
inversions
molecules
Surface potential
excitation
Ionization
Trajectories
trajectories
ionization
life (durability)
Atoms

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 journalArticle

@article{b0fafdae756749d1ae26e061388ebd4d,
title = "Intramolecular motion in DIET: desorption and dissociation of chemisorbed ammonia",
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.",
author = "Burns, {A. R.} and Ellen Stechel and Jennison, {D. R.}",
year = "1995",
month = "6",
day = "3",
doi = "10.1016/0168-583X(95)00053-4",
language = "English",
volume = "101",
pages = "41--48",
journal = "Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms",
issn = "0168-583X",
publisher = "Elsevier",
number = "1-2",

}

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.

UR - http://www.scopus.com/inward/record.url?scp=0001867281&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001867281&partnerID=8YFLogxK

U2 - 10.1016/0168-583X(95)00053-4

DO - 10.1016/0168-583X(95)00053-4

M3 - Article

AN - SCOPUS:0001867281

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 -