Hyperthermal CI Atom Beam Produced by Laser Vaporization of Cryogenic ICI Films

1992 ◽  
Vol 285 ◽  
Author(s):  
Gabriela C. Weaver ◽  
Francis X. Campos ◽  
Stephen R. Leone
Keyword(s):  
Laser Vaporization ◽  
Atom Beam ◽  
Pulsed Nd:Yag Laser ◽  
Atom Flux ◽  
Atom Source ◽  
Vaporization Process ◽  
Cl Atoms ◽  
Cl Atom ◽  
532 Nm ◽  
Mean Kinetic Energy

ABSTRACTA source of energetic, neutral Cl atoms is produced by laser vaporization of cryogenic ICI films using either the 532 nm or 266 nm output of a pulsed Nd:YAG laser. The pulsed Cl mean kinetic energy can be tuned from 0.4 eV to 3.4 eV by varying the laser repetition rate or the rate of deposition of the ICl film. Also present in the beam are ICI, I, I2, and Cl2 The heavier species all have lower velocities than the Cl atoms, and this difference in velocities can be accentuated by vaporizing thinner films. Using a mechanical velocity chopper, the fastest part of the beam can be selected, which consists of > 90% Cl atoms. Results suggest that the vaporization process involves a directed mass flow in which the heavier molecules are propelled to higher velocities by the faster Cl atom flux. The atom source may be used for selective etching studies.

The Bond N -Cl. A Spectroscopic (35Cl-NQR, IR) Investigation

1994 ◽  
Vol 49 (6) ◽  
pp. 695-702 ◽  
Author(s):  
B. Thimme Gowda ◽  
Alarich Weiss
Keyword(s):  
Phenyl Ring ◽  
Electron Distribution ◽  
Inductive Effect ◽  
Aqueous Media ◽  
Phenyl Group ◽  
Vibration Frequencies ◽  
Resonance Frequencies ◽  
35Cl Nqr ◽  
Cl Atoms ◽  
Cl Atom

Abstract Chlorine bound to nitrogen is an interesting oxidizing agent in aqueous, partial aqueous and non-aqueous media. One can assume that the oxidizing action of the chlorine depends on the polarization of the Cl atom in the bond N -Cl which will depend on the electron distribution in the ligands R and R″ of the configuration R -NCl -CO -R″. 17 compounds were synthesized with R = substituted phenyl radical C6H5-y Xy, X = Cl, NO2, R″ = CH2Cl. The 35Cl NQR frequencies are observed in the range 52 to 54 MHz (T = 77 K) for the Cl(N) 34 to 37 MHz for the phenyl chlorines and the CH2Cl group. Their temperature dependence was followed up to 300 K. Therefrom the assignment of the resonance to certain Cl-atoms in the molecules is possible. Generally, the substitution of a negative substituent X (Cl, NO2) in the phenyl ring raises the resonance frequencies; the influence of the CH2Cl group on the N -Cl bond is weak. Strong is the influence of the carbonyl group on the N -C l bond. The IR group frequencies ν(C = O) are found in the range 1680 ≤ ν (C = O)/ cm−1≤ 1717, shifted up by ≤ 20 cm−1 compared to the corresponding acetamide R ⎯ NH ⎯CO ⎯ R″. Influence of the phenyl ring substitution on ν (C = O) does not follow a simple law of inductive effect. Also a correlation between the vibration frequencies of the N ⎯ Cl group and the phenyl group substitution is not found.

Die Reaktionen chlorierter Äthylene mit hydratisierten Elektronen und OH-Radikalen in wäßriger Lösung / The Reaction of Chlorinated Ethylenes with Hydrated Electrons and OH-Radicals in Aqueous Solution

1971 ◽  
Vol 26 (11) ◽  
pp. 1108-1116 ◽  
Author(s):  
R. Köster ◽  
K.-D. Asmus
Keyword(s):  
Rate Constant ◽  
Oh Radicals ◽  
Capture Process ◽  
Chlorinated Ethylenes ◽  
Diffusion Controlled ◽  
Hydrated Electrons ◽  
Cl Atoms ◽  
Type Radical ◽  
Cl Atom ◽  
Steric Hinderance

The reactions of chlorinated ethylenes with hydrated electrons and OH radicals have been investigated by using the method of pulse radiolysis. In addition γ-ray experiments were carried out. The reduction of the solutes occurs via a dissoziation electron capture process. The rate constant for the reaction of eaq⊖ with the more chlorinated compounds is essentially diffusion controlled (k= (1 - 2×1010 l-mole-1 sec-1). Vinylchloride and 1,2-trans-dichloroethylene react more slowly. This can be related to the higher stability of the C-Cl bond in these compounds.Hydroxyl radicals add to the C=C double bond of the chlorinated ethylenes. The rate constant for the reaction with vinylchloride was determined to 7.1 × 109 1 · mole-1 sec-1, and decreases with increasing degree of chlorination of the ethylenes. This effect is explained by the decreasing electron density on the C-atoms and steric hinderance. The hydroxyl radical always adds to the C-atom carrying the smallest number of Cl-atoms. In its reaction with 1,2-dichloro-, trichloro- and tetrachloroethylene a radical is produced with an OH group and a Cl-atom on the same C-atom. It eliminates HCl to form a C=O bond with k>7 × 105 sec-1. The type radical produced in this reaction has an optical absorption in the near UV (ε265 nm = (1-3)×103 1 · mole-1 cm-1).The OH radical addition products of vinylchloride and 1,1-dichloroethylene do not eliminate HCl and have no absorption in the visible and near UV.

Reductive dechlorination pathways of chloro organics under anaerobic conditions

1996 ◽  
Vol 34 (5-6) ◽  
pp. 489-494 ◽  
Author(s):  
Sridhar Susarla ◽  
Shigeki Masunaga ◽  
Yoshitaka Yonezawa
Keyword(s):  
Reductive Dechlorination ◽  
Organic Chemicals ◽  
Anaerobic Conditions ◽  
Sediment Slurry ◽  
Transformation Pathways ◽  
Lag Period ◽  
Cl Atoms ◽  
Cl Atom

The transformation pathways of chloroanilines (CAs), chlorobenzenes (CBs) and chlorophenols (CPs) were examined in anaerobic sediment collected from the Tsurumi river, Japan. The sediment was pre-exposed to various organic chemicals from the surrounding industries and appears to be sulfidogenic. Experiments were carried out for each compound in the sediment slurry, which was spiked at a desired concentration. The transformation of the parent substrate and the appearance of its metabolites were monitored for a year. All the compounds transformed without any lag period. For CBs, the preferential Cl removal was in the order: two Cl atoms on adjacent carbon atoms > one Cl atom on adjacent carbon > no adjacent Cl atom on the carbon. In case of CPs, ortho dechlorination was the preferred pathway, while for CAs, sequential removal of ortho and para positions was observed.

Evaluation of the Laser Ablation of Transition Metals/Metal Compounds by Time-of-Flight and Optical Spectroscopy

1992 ◽  
Vol 285 ◽  
Author(s):  
Terry L. Thiem ◽  
Lyn R. Watson ◽  
James A. Gardner ◽  
Rainer A. Dressier ◽  
Richard H. Salter ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Kinetic Studies ◽  
Laser Vaporization ◽  
Metal Compounds ◽  
Short Sample ◽  
Atomic Beams ◽  
Atom Source ◽  
Chloride Salts ◽  
Time Of Flight Spectroscopy ◽  
Initial Results

ABSTRACTA fast pulsed beam of neutral metal atoms is produced by laser vaporization ofa solid metal or metal compound sample in a modified high-temperature mass spectrometer. Atomic beams of several eV kinetic energy are generated as measured using time-of-flight spectroscopy. The energy range can be controlled with the laser power, similar to studies conducted on thin metal films. The solid samples, however, overcome the problem of short sample lifetime associated with irradiating thin films. Samples have been irradiated for several hours without observing a change in beam intensity or energy, thus offering an interesting source for kinetic studies. Initial results of studies done on copper, nickel, zinc and related oxide, sulfide, bromide, and chloride salts will be discussed as to their applicability to serve as a fast atom source. Spectroscopic data from these compounds will also be presented.

scholarly journals Tropospheric OH and Cl levels deduced from non-methane hydrocarbon measurements in a marine site

2007 ◽  
Vol 7 (17) ◽  
pp. 4661-4673 ◽  
Author(s):  
C. Arsene ◽  
A. Bougiatioti ◽  
M. Kanakidou ◽  
B. Bonsang ◽  
N. Mihalopoulos
Keyword(s):  
Eastern Mediterranean ◽  
Regional Scale ◽  
Oh Radicals ◽  
Atom Concentration ◽  
Diel Variations ◽  
Marine Site ◽  
Cl Atoms ◽  
Cl Atom ◽  
Good Agreement

Abstract. In situ continuous hourly measurements of C2–C8 non-methane hydrocarbons (NMHCS) have been performed from March to October 2006 at two coastal locations (natural and rural) on the island of Crete, in the Eastern Mediterranean. Well defined diel variations were observed for several short lived NMHCS (including ethene, propene, n-butane, n-pentane, n-hexane, 2-methyl-pentane). The daytime concentration of hydroxyl (OH) radicals estimated from these experimental data varied from 1.3×106 to ~4.0×106 radical cm−3, in good agreement with box-model simulations. In addition the relative variability of various hydrocarbon pairs (at least 7) was used to derive the tropospheric levels of Cl atoms. The Cl atom concentration has been estimated to range between 0.6×104 and 4.7×104 atom cm−3, in good agreement with gaseous hydrochloric acid (HCl) observations in the area. Such levels of Cl atoms can be of considerable importance for the oxidation capacity of the troposphere on a regional scale.

scholarly journals Crystal structure ofcatena-poly[[chlorido(4,4′-dimethyl-2,2′-bipyridine-κ2N,N′)copper(II)]-μ-chlorido]

2015 ◽  
Vol 71 (6) ◽  
pp. 624-627
Author(s):  
Rafaela Nita ◽  
Jeffrey R. Deschamps ◽  
Scott A. Trammell ◽  
D. Andrew Knight
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Title Compound ◽  
Trigonal Bipyramidal Geometry ◽  
Trigonal Bipyramidal ◽  
Bipyridine Ligand ◽  
Cl Atoms ◽  
Cl Atom ◽  
Distorted Trigonal Bipyramidal

The title compound, [CuCl2(C12H12N2)]n, was obtainedviaa DMSO-mediated dehydration of Cu(4,4′-dimethyl-2,2′-bipyridine)copper(II)·0.25H2O. The central CuIIatom is coordinated in a distorted trigonal–bipyramidal geometry by two N atoms of a chelating 4,4′-dimethyl-2,2′-bipyridine ligand [average Cu—N = 2.03 (3) Å] and three Cl atoms, one terminal with a short Cu—Cl bond of 2.2506 (10) Å, and two symmetry-equivalent and bridging bonds. The bridging Cl atom links the CuIIions into chains parallel to [001]viaone medium and one long Cu—Cl bond [2.3320 (10) and 2.5623 (9) Å]. The structure displays both inter- and intramolecular C—H...Cl hydrogen bonding.

scholarly journals Primary vs. secondary H-atom abstraction in the Cl-atom reaction with n-pentane

2017 ◽  
Vol 19 (2) ◽  
pp. 1614-1626 ◽  
Author(s):  
Shubhrangshu Pandit ◽  
Balázs Hornung ◽  
Greg T. Dunning ◽  
Thomas J. Preston ◽  
Kristian Brazener ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Classical Trajectory ◽  
Velocity Map Imaging ◽  
Trajectory Calculations ◽  
Cl Atoms ◽  
Cl Atom

Velocity map imaging measurements and quasi-classical trajectory calculations on a newly developed, global potential energy surface combine to reveal the detailed mechanisms of reaction of Cl atoms with n-pentane.

scholarly journals Tropospheric OH and Cl levels deduced from non-methane hydrocarbon measurements in a marine site

2007 ◽  
Vol 7 (3) ◽  
pp. 6329-6356 ◽  
Author(s):  
C. Arsene ◽  
A. Bougiatioti ◽  
M. Kanakidou ◽  
B. Bonsang ◽  
N. Mihalopoulos
Keyword(s):  
Eastern Mediterranean ◽  
Regional Scale ◽  
Diurnal Variations ◽  
Oh Radicals ◽  
Atom Concentration ◽  
Marine Site ◽  
Cl Atoms ◽  
Cl Atom ◽  
Good Agreement

Abstract. In situ continuous hourly measurements of C2-C8 non-methane hydrocarbons (NMHCS) have been performed from March to October 2006 at two coastal locations on the island of Crete, in the Eastern Mediterranean. Well defined diurnal variations were observed for several short lived NMHCS (including ethene, propene, n-butane, n-pentane, n-hexane, 2-methyl-pentane). The daytime concentration of hydroxyl (OH) radicals estimated from these experimental data varied from 1.3×106 to ~4.0×106 radical cm−3, in good agreement with box-model simulations. In addition the relative variability of various hydrocarbon pairs (at least 7) was used to derive the tropospheric levels of Cl atoms. The Cl atom concentration has been estimated to range between 0.6×104 and 4.7×104 atom cm−3, in good agreement with gaseous hydrochloric acid (HCl) observations in the area. Such levels of Cl atoms can be of considerable importance for the oxidation capacity of the troposphere on a regional scale.

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