A discharge investigation of hydrogen and deuterium atom formation, and parahydrogen and orthodeuterium reconversion

Andrews, Lester; Wang, Xuefeng

doi:10.1063/1.1779215

Cited by 12 publications

(8 citation statements)

References 21 publications

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“…In the laser ablation process, H−H bonds are broken, and H atoms, H + , and electrons are produced. The H + is trapped in the argon lattice to give Ar n H + and Ar n D + at 903.6 and 643.1 cm -1 that have been assigned in early reports. , The H atom is attached to O 2 to give HO 2 radical (1388.4, 1101.9 cm -1 ) and D atom to O 2 to give DO 2 (1019.8 cm -1 ). , The O 3 , O 4 + , O 4 - , and O 6 - ions were also observed as common products as in laser-ablated metal atom reactions with O 2 . − In the solid H 2 and D 2 experiments, H (D) and H - (D - ) are trapped in solid H 2 (D 2 ) to form clusters, which have been identified in previous papers. , …”

Section: Resultsmentioning

confidence: 78%

Zinc and Cadmium Dihydroxide Molecules: Matrix Infrared Spectra and Theoretical Calculations

Wang

Andrews

2005

J. Phys. Chem. A

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Laser-ablated zinc and cadmium atoms were mixed uniformly with H2 and O2 in excess argon or neon and with O2 in pure hydrogen or deuterium during deposition at 8 or 4 K. UV irradiation excites metal atoms to insert into O2 producing OMO molecules (M = Zn, Cd), which react further with H2 to give the metal hydroxides M(OH)2 and HMOH. The M(OH)2 molecules were identified through O-H and M-O stretching modes with appropriate HD, D2, (16,18)O2, and (18)O2 isotopic shifts. The HMOH molecules were characterized by O-H, M-H, and M-O stretching modes and an M-O-H bending mode, which were particularly strong in pure H2/D2. Analogous Zn and Cd atom reactions with H2O2 in excess argon produced the same M(OH)2 absorptions. Density functional theory and MP2 calculations reproduce the IR spectra of these molecules. The bonding of Group 12 metal dihydroxides and comparison to Group 2 dihydroxides are discussed. Although the Group 12 dihydroxide O-H stretching frequencies are lower, calculated charges show that the Group 2 dihydroxide molecules are more ionic.

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Section: Resultsmentioning

confidence: 78%

Zinc and Cadmium Dihydroxide Molecules: Matrix Infrared Spectra and Theoretical Calculations

Wang

Andrews

2005

J. Phys. Chem. A

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“…These researchers found H atom diffusion rates 100 times larger than the previous ESR measurements of H atom recombination and ascribed the difference to the intermolecular interactions of H + NO compared to H + H . Andrews and co-workers studied the induced IR transitions in solid hydrogen (and enriched pH 2 solids) produced by the presence of an H atom either by laser ablating metal atoms into the solids or by direct condensation of hydrogen gas subjected to tesla coil discharge in a quartz tube. , In these studies, H atom-induced peaks in pH 2 were identified at 4151.8 cm –1 , which show intensity half-lives compatible with the ESR measurements. More recently, Cao et al performed 193 nm photolysis studies on HCOOH/HBr mixtures in a Kr matrix aimed at studying the H + HCOOH reaction at low temperature .…”

Section: Introductionmentioning

confidence: 99%

Reactions of Atomic Hydrogen with Formic Acid and Carbon Monoxide in Solid Parahydrogen I: Anomalous Effect of Temperature

et al. 2014

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Low-temperature condensed phase reactions of atomic hydrogen with closed-shell molecules have been studied in rare gas matrices as a way to generate unstable chemical intermediates and to study tunneling-driven chemistry. Although parahydrogen (pH2) matrix isolation spectroscopy allows these reactions to be studied equally well, little is known about the analogous reactions conducted in a pH2 matrix host. In this study, we present Fourier transform infrared (FTIR) spectroscopic studies of the 193 nm photoinduced chemistry of formic acid (HCOOH) isolated in a pH2 matrix over the 1.7 to 4.3 K temperature range. Upon short-term irradiation the HCOOH readily undergoes photolysis to yield CO, CO2, HOCO, HCO and H atoms. Furthermore, after photolysis at 1.9 K tunneling reactions between migrating H atoms and trapped HCOOH and CO continue to produce HOCO and HCO, respectively. A series of postphotolysis kinetic experiments at 1.9 K with varying photolysis conditions and initial HCOOH concentrations show the growth of HOCO consistently follows single exponential (k = 4.9(7)x10(-3) min(-1)) growth kinetics. The HCO growth kinetics is more complex displaying single exponential growth under certain conditions, but also biexponential growth at elevated CO concentrations and longer photolysis exposures. By varying the temperature after photolysis, we show the H atom reaction kinetics qualitatively change at ∼2.7 K; the reaction that produces HOCO stops at higher temperatures and is only observed at low temperature. We rationalize these results using a kinetic mechanism that involves formation of an H···HCOOH prereactive complex. This study clearly identifies anomalous temperature effects in the reaction kinetics of H atoms with HCOOH and CO in solid pH2 that deserve further study and await full quantitative theoretical modeling.

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“…This simply shows that the b-type transition reflects the total of satellite and monomer peaks, while for the a-type transition these two contributions are spectroscopically resolved and can be detected separately. If instead we make a correlation plot of the a-type sum (monomer plus satellites) versus the b-type transition intensity, then we observe a strong linear correlation with a fitted slope of 0.6489 (17). Indeed, this is what is expected based on the transitions strengths of a-type and b-type HDO ν 2 bend transitions, which show that the transition dipole has a larger projection along the inertial B axis [29].…”

Section: Shown Inmentioning

confidence: 69%

“…Fushitani and Momose used FTIR spectroscopy [15] to measure the H atom diffusion rate by studying the H + NO → HNO tunneling reaction after the in situ photolysis of NO in solid pH 2 at 5.2 K. In these studies the H atoms are produced as by-products of the NO photolysis, and the H-atom diffusion rate is determined from the growth in the IR absorption intensity of HNO. Andrews and co-workers studied the induced IR transitions in solid hydrogen (and enriched pH 2 solids) produced by the presence of an H atom either by laser ablating metal atoms into the solids or by direct condensation of hydrogen gas subjected to tesla coil discharge in a quartz tube [16,17]. In these studies H atom induced peaks in pH 2 were identified at 4151.8 cm -1 which show intensity half-lives compatible with the ESR measurements.…”

Section: Introductionmentioning

confidence: 75%

Transient HDO rovibrational satellite peaks in solid parahydrogen: Evidence of hydrogen atoms or vacancies?

Wonderly

Anderson

2012

Low Temperature Physics

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We present FTIR studies of the 193 nm photolysis of fully deuterated formic acid (DCOOD) isolated in solid parahydrogen at 1.9 K which show evidence of transient HDO rovibrational satellite peaks. The S1 and S2 satellite peaks are readily detected for a-type (1 01 ← 0 00 ) rovibrational transitions of HDO either during or immediately after photolysis. Intensity measurements show the HDO b-type (1 11 ← 0 00 ) rovibrational transitions have satellite peaks as well, but due to the greater linewidth of these absorptions, the satellite peaks cannot be spectroscopically resolved from the monomer transition and are therefore difficult to detect. These newly identified HDO satellite peaks may result from the HDO photoproduct being formed next to an H atom or a vacancy in the parahydrogen solid. The development of the infrared spectroscopy of these satellite peaks can provide a new means to study radiation effects on low-temperature hydrogen solids doped with chemical species.

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A discharge investigation of hydrogen and deuterium atom formation, and parahydrogen and orthodeuterium reconversion

Cited by 12 publications

References 21 publications

Zinc and Cadmium Dihydroxide Molecules: Matrix Infrared Spectra and Theoretical Calculations

Zinc and Cadmium Dihydroxide Molecules: Matrix Infrared Spectra and Theoretical Calculations

Reactions of Atomic Hydrogen with Formic Acid and Carbon Monoxide in Solid Parahydrogen I: Anomalous Effect of Temperature

Transient HDO rovibrational satellite peaks in solid parahydrogen: Evidence of hydrogen atoms or vacancies?

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