THE QUENCHING OF POTASSIUM RESONANCE RADIATION BY HYDROCARBONS

1959 ◽  
Vol 37 (2) ◽  
pp. 341-344
Author(s):  
E. A. Cherniak ◽  
W. M. Smith
Keyword(s):  
Cross Sections ◽  
Resonance Radiation ◽  
Unsaturated Hydrocarbons ◽  
Saturated Hydrocarbons

The quenching of the resonance radiation of potassium by some unsaturated and saturated hydrocarbons has been examined at 67 °C. The behavior was found to be almost identical with that previously observed with sodium, the saturated hydrocarbons quenching to a negligible extent, the unsaturated hydrocarbons exhibiting cross sections with potassium not significantly different from those exhibited towards sodium.

scholarly journals The quenching of the resonance radiation of sodium

1940 ◽  
Vol 176 (966) ◽  
pp. 295-312 ◽  
Keyword(s):  
Cross Section ◽  
Effective Cross Section ◽  
Sodium Atom ◽  
Resonance Radiation ◽  
Inert Gases ◽  
Tertiary Amines ◽  
Unsaturated Hydrocarbons ◽  
Saturated Hydrocarbons ◽  
The Difference ◽  
Eyring's Theory

The effective cross-section for quenching of sodium resonance radiation by the saturated and unsaturated hydrocarbons, tertiary amines and several diatomic molecules has been measured. The results indicate that with regard to quenching ability the gases fall into two groups, one comprising the saturated hydrocarbons and the inert gases and the other the unsaturated hydrocarbons and the amines. The difference in behaviour is too pronounced to be explained in terms of the discrepancy between the amount of energy the sodium atom gives up and the quenching molecule can receive, but may be attributed to the presence of unsaturation in the molecule. Within any one series the number of atoms in the molecule apart from the unsaturated centre seems to have little influence on the quenching ability, and it has been concluded that the quenching ability may be regarded as proceeding from a centre of unsaturation. The results have been qualitatively considered in the light of Stearn and Eyring’s theory of non-adiabatic reactions, and in the terminology of the theory of the intermediate complex we may say that the presence of unsaturation manifests itself in a relatively large transmission coefficient.

NMR studies of hydrocarbons solubilized in aqueous micellar solutions

1991 ◽  
Vol 69 (5) ◽  
pp. 822-833 ◽  
Author(s):  
Roderick E. Wasylishen ◽  
Jan C. T. Kwak ◽  
Zhisheng Gao ◽  
Elisabeth Verpoorte ◽  
J. Bruce MacDonald ◽  
...  
Keyword(s):  
Alkyl Chain ◽  
Chemical Shifts ◽  
Nmr Relaxation ◽  
Spin Lattice Relaxation ◽  
Ionic Surfactant ◽  
Nmr Studies ◽  
Unsaturated Hydrocarbons ◽  
Saturated Hydrocarbons ◽  
Surfactant Micelle ◽  
H Nmr

Information concerning the solubilization of hydrocarbons in ionic surfactant micelles was obtained from 2H NMR relaxation, 1H NMR chemical shifts, and 1H NMR paramagnetic relaxation measurements. The rotational motion of deuterated hydrocarbons, which is related to the micellar microviscosity at the location of the hydrocarbons, was probed by 2H NMR relaxation. The relaxation data are interpreted using both the two-step and the single-step models, and the results are discussed in terms of the micellar microviscosity and the location of the hydrocarbons in micelles. The location of the hydrocarbons in micelles was further investigated by determining the aromatic ring current-induced 1H chemical shifts along the surfactant alkyl chain and by comparing the 1H spin-lattice relaxation enhancement of the hydrocarbons and the surfactant alkyl chain, induced by Mn2+ on the micellar surface. The hydrocarbons used include benzene, naphthalene, acenaphthalene, triphenylene, cyclohexane, cyclododecane, and tert-butylcyclohexane and the surfactants studied are hexadecyl-, tetradecyl-, and dodecyltrimethylammonium bromide; hexadecyl-, tetradecyl-, and dodecylpyridinium halide; and sodium dodecyl sulfate. The results indicate that the micellar microviscosity at the location of saturated hydrocarbons is approximately 5 cP for both the cationic and anionic micelles, whereas the micellar microviscosity at the location of unsaturated hydrocarbons is much higher. The unsaturated hydrocarbons are found to reside primarily near the surfactant headgroup in the cationic micelles, but are distributed evenly throughout the anionic SDS micelles. The saturated hydrocarbons appear to be located in the interior of the micelles. Key words: NMR, relaxation, solubilization, surfactant, micelle.

Sensitized fluorescence in thallium induced in collisions with Hg(63P1) atoms

1978 ◽  
Vol 56 (7) ◽  
pp. 891-896 ◽  
Author(s):  
M. K. Wade ◽  
M. Czajkowski ◽  
L. Krause
Keyword(s):  
Cross Sections ◽  
Ground State ◽  
Excitation Transfer ◽  
Resonance Radiation ◽  
Resonance Fluorescence ◽  
Collisional Excitation ◽  
Vapor Mixture ◽  
Sensitized Fluorescence ◽  
Intensity Measurements ◽  
Metallic Vapor

The transfer of excitation from excited mercury atoms to ground-state thallium atoms was investigated using techniques of sensitized fluorescence. A Hg–Tl vapor mixture contained in a quartz cell was irradiated with Hg 2537 Å resonance radiation which caused the mercury atoms to become excited to the 63P1, state. Subsequent collisions between the Hg(63P1) and Tl(62P1/2) atoms resulted in the population of the 82S1/2, 62D, and 72S1/2 thallium states, whose decay gave rise to sensitized fluorescence of wavelengths 3231, 3520, 3776, and 5352 Å. Intensity measurements on the sensitized fluorescence and on the Hg 2537 Å resonance fluorescence, observed at right angles to the direction of excitation, yielded cross sections of 3.0, 0.3, and 0.05 Å2 for collisional excitation transfer from Hg(63P1) to the 82S1/2, 62D, and 72S1/2 states in thallium, respectively. The results are fully consistent with previously determined cross sections for excitation transfer in other binary metallic vapor systems.

Notizen: Desorientierung von optisch ausgerichteten Na-Atomen durch Stöße mit gesättigten Kohlenwasserstoffen/Disorientation of Optically Oriented Na-atoms in Collisions with Saturated Hydrocarbons

1973 ◽  
Vol 28 (5) ◽  
pp. 793-794 ◽  
Author(s):  
H. Soboll
Keyword(s):  
Cross Sections ◽  
Strong Increase ◽  
Buffer Gas ◽  
Spin Orbit ◽  
Saturated Hydrocarbons ◽  
The Cross

Cross sections for collisionally induced disorientation of of the Na (3 2S½) sublevels have been measured for the C1 - C4 saturated hydrocarbons. The strong increase of the cross sections with the number of buffer gas electrons can be explained by using the model of spin-orbit-relaxation.

THE QUENCHING OF POTASSIUM RESONANCE RADIATION BY HYDROGEN AND DEUTERIUM

1954 ◽  
Vol 32 (10) ◽  
pp. 961-968 ◽  
Author(s):  
W. M. Smith ◽  
J. A. Stewart ◽  
G. W. Taylor
Keyword(s):  
Cross Sections ◽  
Resonance Radiation ◽  
Temperature Range

The quenching of the resonance radiation of potassium by hydrogen and deuterium has been studied over the temperature range 71 °C to 83 °C. The quenching cross sections at 76 °C were found to be 1.56 × 10−16 cm2 and 1.10 × 10−16 cm2 respectively.

Collisional Depolarization of Mercury Resonance Radiation

1973 ◽  
Vol 51 (7) ◽  
pp. 724-726 ◽  
Author(s):  
R. A. Phaneuf ◽  
J. Pitre ◽  
K. Hammond ◽  
L. Krause
Keyword(s):  
Cross Sections ◽  
Resonance Radiation

The depolarization of mercury resonance radiation (2537 Å), induced in collisions of Hg(63p1) atoms with various buffer gases, has been investigated using the method of delayed coincidences. The experiments yielded the following depolarization cross sections. Hg–He, 37.8 Å2; Hg–Ne, 43.5 Å2; Hg–Ar, 72.9 Å2; Hg–Kr, 101 Å2; Hg–Xe, 144 Å2; Hg–N2, 120 Å2.

The determination of cross sections for the quenching of resonance radiation of metal atoms II. Results for potassium, rubidium and caesium

1968 ◽  
Vol 303 (1475) ◽  
pp. 453-465 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Cross Sections ◽  
Resonance Radiation ◽  
Fluorescence Technique ◽  
Metal Atoms

The flame fluorescence technique has been used to study the fluorescence of the metals potassium, rubidium and caesium. Measurements of the intensity of fluorescence of each of these metals in isothermal groups of hydrogen-oxygen flames diluted with each of the gases argon, helium, nitrogen and carbon dioxide have given the following values (Å 2 ) for the square of the distance between the centres of colliding species, σ 2 : for potassium: σ 2 H 2 = 1.03 ± 0.05 σ 2 H 2 O = 0.9 ± 0.3 σ 2 Ar < 0.2 σ 2 He < 0.08 σ 2 N 2 = 5.6 ± 0.3 σ 2 CO = 12.4 ± 0.8 σ 2 CO 2 = 21.4 ± 1.0 σ 2 O 2 = 15.5 ± 1.5 for rubidium: σ 2 H 2 = 0.61 ± 0.1 σ 2 H 2 O = 1.27 ± 0.15 σ 2 Ar < 0.3 σ 2 He < 0.11 σ 2 N 2 = 6.1 ± 0.6 σ 2 CO = 11.8 ± 2.0 σ 2 CO 2 = 24 ± 2 σ 2 O 2 = 25 ± 5 for caesium: σ 2 H 2 = 1.7 ± 0.3 σ 2 H 2 O = 5.5 ± 1.6 σ 2 Ar < 0.9 σ 2 He < 0.4 σ 2 N 2 = 25 ± 6

The determination of cross-sections for the quenching of resonance radiation of metal atoms. IV. Results for lithium

1968 ◽  
Vol 306 (1486) ◽  
pp. 413-421 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Cross Section ◽  
Cross Sections ◽  
Hollow Cathode ◽  
Alkali Metals ◽  
Resonance Radiation ◽  
The Other ◽  
Fluorescence Technique ◽  
Metal Atoms

The flame fluorescence technique has been used to study the fluorescence of lithium in sets of isothermal hydrogen-oxygen flames diluted with each of the gases argon, nitrogen and carbon dioxide. The measurements have given the following values (Å 2 ) for the quenching cross-sections, σ 2 , of lithium in the 2 p 2 P state: σ 2 H 2 = 5⋅2, σ 2 H 2 O ═ 1⋅9, σ 2 N 2 ═ 6⋅75, σ 2 CO ═ 12⋅6, σ 2 CO 2 ═ 9⋅2, σ 2 Ar ≼ 0⋅3. The cross-section is defined as the square of the distance between centres of colliding species. These values are compared with those previously reported (Jenkins 1966, 1968) for the other alkali metals and their interpretation discussed. Details of the high intensity hollow cathode lamp used as a source of lithium resonance radiation are also given.

The determination of cross sections for quenching of resonance radiation of metal atoms III. Results for thallium

1968 ◽  
Vol 303 (1475) ◽  
pp. 467-475 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Cross Section ◽  
Cross Sections ◽  
Rate Constants ◽  
Resonance Radiation ◽  
Metal Atoms ◽  
The Cross

The intensity of fluorescence of thallium has been measured in hydrogen-oxygen flames diluted with each of the gases, argon, helium, nitrogen and carbon dioxide and the measurements used to obtain the following values for the quenching cross section (Å 2 ) for the 7 s 2 S ½ state of thallium σ 2 H 2 = 0.03, σ 2 O 2 = 13.2 ± 1.5, σ 2 N 2 = 6.4 ± 0.2, σ 2 H 2 O = 1.75 ± 0.2, σ 2 CO = 13.6 ± 0.8, σ 2 CO 2 = 32.5 ± 1.5, σ 2 Ar ≤ 0.1, σ 2 He ≤ 0.12. These values for the cross sections have been used to re-calculate the rate constants of the reactions, Tl + H + X → H X + Tl*, where X = H, OH, Cl or Br, from the data obtained by Phillips & Sugden (1961). The re-calculated values are lower than the original ones by a factor of 2.2.

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