Guided ion beam and theoretical study of the reactions of Hf{sup +} with H{sub 2}, D{sub 2}, and HD

Journal Article · Tue Sep 28 04:00:00 EDT 2010 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.3482663· OSTI ID:21559918

Hinton, Christopher S; Armentrout, P B ^[1]

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1. Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112 (United States)

The kinetic energy dependences of reactions of the third-row transition metal cation Hf{sup +} with H{sub 2}, D{sub 2}, and HD were determined using a guided ion beam tandem mass spectrometer. A flow tube ion source produces Hf{sup +} in its {sup 2}D (6s{sup 2}5d{sup 1}) electronic ground state level. Corresponding state-specific reaction cross sections are obtained. The kinetic energy dependences of the cross sections for the endothermic formation of HfH{sup +} and HfD{sup +} are analyzed to give a 0 K bond dissociation energy of D{sub 0}(Hf{sup +}-H)=2.11{+-}0.08 eV. Quantum chemical calculations at several levels of theory performed here generally overestimate the experimental bond energy but results obtained using the Becke-half-and-half-LYP functional show good agreement. Theory also provides the electronic structures of these species and the reactive potential energy surfaces. Results from the reactions with HD provide insight into the reaction mechanisms and indicates that Hf{sup +} reacts via a statistical mechanism. We also compare this third-row transition metal system with the first-row and second-row congeners, Ti{sup +} and Zr{sup +}, and find that Hf{sup +} has a weaker M{sup +}-H bond. As most third-row transition metal hydride cation bonds exceed their lighter congeners, this trend is unusual but can be understood using promotion energy arguments.

• OSTI ID: 21559918
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 12 Vol. 133; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BEAMS
BINDING ENERGY
CALCULATION METHODS
CATIONS
CHARGED PARTICLES
COLLISIONS
COMPARATIVE EVALUATIONS
CROSS SECTIONS
DENSITY FUNCTIONAL METHOD
DEUTERIUM
DISSOCIATION ENERGY
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY
EVALUATION
HAFNIUM IONS
HYDRIDES
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ION BEAMS
ION COLLISIONS
ION-MOLECULE COLLISIONS
IONS
ISOTOPES
KINETIC ENERGY
KINETICS
LIGHT NUCLEI
MASS SPECTROMETERS
MEASURING INSTRUMENTS
METALS
MOLECULE COLLISIONS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
POTENTIAL ENERGY
REACTION KINETICS
SPECTROMETERS
STABLE ISOTOPES
TITANIUM IONS
TRANSITION ELEMENTS
VARIATIONAL METHODS
ZIRCONIUM IONS