The hydrogen atom-deuterium molecule reaction: Experimental determination of product quantum state distributions

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5124718

Rinnen, K

The H + H{sub 2} atom exchange reaction (and its isotopic analogs) is the simplest neutral bimolecular chemical reaction because of the small number of electrons in the system and the lightness of the nuclei. The H{sub 3} potential energy surface (PES) is the most accurately known reactive surface (LSTH surface); there have been both quasiclassical trajectory (QCT) and quantal calculations performed on it. This is one of the few systems for which theory is ahead of experiment, and many theoretical predictions await experimental comparison. The H + D{sub 2} {yields} HD + D reaction is studied using thermal D{sub 2}({approximately}298 K) and translationally hot hydrogen atoms. Photolysis of HI at 266 nm generates H atoms with center-of-mass collision energies of 1.3 and 0.55 eV, both of which are above the classical reaction barrier of 0.42 eV. The rovibrational population distribution of the molecular product is measured by (2+1) resonance-enhanced multiphoton ionization (REMPI). A major effort has been directed toward calibrating the (2+1) REMPI detection procedure, to determine quantitatively the relationship between ion signals and relative quantum state populations for HD. An effusive, high-temperature nozzle has been constructed to populate thermally the high rovibrational levels observed in the reaction. The results are compared to theoretical calculations of the E,F {sup 1}{Sigma}{sub g}{sup +} - X {sup 1}{Sigma}{sub g}{sup +} two-photon transition moments. For the H + D{sub 2} reaction, the populations of all energetically accessible HD product levels are measured. Specifically, the following levels are observed: HD(v = 0, J = 0-15), HD(v = 1, J = 0-12), and HD(v = 2, J = 0-8). Of the available energy, 73% is partitioned into product translation, 18% into HD rotation, and 9% into HD vibration.

• Research Organization: Stanford Univ., CA (United States)
• OSTI ID: 5124718
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
400701 -- Radiochemistry & Nuclear Chemistry-- Hot-Atom Chemistry
ATOMS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
DEUTERIUM
ELEMENTS
ENERGY LEVELS
EXPERIMENTAL DATA
HALOGEN COMPOUNDS
HOT ATOM CHEMISTRY
HYDRIODIC ACID
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
INFORMATION
INORGANIC ACIDS
IODINE COMPOUNDS
ISOTOPE EFFECTS
ISOTOPES
KINETICS
LIGHT NUCLEI
MOLECULES
NONMETALS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADIOCHEMISTRY
REACTION KINETICS
STABLE ISOTOPES