Spectra of H2–Ne and D2–Ne Van der Waals Complexes in the Collision-Induced Fundamental Bands of Hydrogen and Deuterium

1972 ◽  
Vol 50 (13) ◽  
pp. 1458-1464 ◽  
Author(s):  
A. R. W. McKellar ◽  
H. L. Welsh
Keyword(s):  
Quantum Number ◽  
Direct Evidence ◽  
Van Der Waals ◽  
Rotational Quantum Number ◽  
Intermolecular Forces ◽  
The Other ◽  
Van Der Waals Complexes ◽  
Intermolecular Potential ◽  
Rare Gas ◽  
Potential Well

Spectra of H2–Ne and D2–Ne Van der Waals complexes accompanying transitions in the collision-induced fundamental bands of hydrogen and deuterium have been obtained with an absorption path of 110 m at temperatures around 27 K in a specially designed multiple-traversal cell. The observed structure is similar to that of H2– and D2–Ar, Kr, and Xe complexes studied earlier, but the number of lines observed for the Ne complexes is fewer because of the shallower intermolecular potential. Well-resolved R and P branches (Δl= ±1, where l is the rotational quantum number of the complex) accompanying the overlap-induced Q1 (0) transitions are analyzed directly to give rotational (B) and centrifugal stretching (D) constants for the complexes. Unlike the other H2– rare gas complexes the spectra accompanying quadrupole-induced transitions show no direct evidence of anisotropy of the intermolecular forces.

Spectra of H2–Ar, H2–Kr, and H2–Xe Van der Waals Complexes in Pressure-Induced Infrared Absorption

1971 ◽  
Vol 49 (2) ◽  
pp. 230-242 ◽  
Author(s):  
A. K. Kudian ◽  
H. L. Welsh
Keyword(s):  
Infrared Absorption ◽  
Path Length ◽  
Vibrational State ◽  
Van Der Waals ◽  
Rotational Quantum Number ◽  
Van Der Waals Complexes ◽  
Intermolecular Potential ◽  
Combination Rules ◽  
Ground Vibrational State ◽  
Lennard Jones

Spectra of H2–Ar, H2–Kr, and H2–Xe Van der Waals complexes, accompanying the Q1(0), Q1(1), S1(0), and S1(1) transitions of the pressure-induced fundamental infrared absorption band of hydrogen, have been studied in gas mixtures at 93–180 °K with a path length of 13 m and total pressures of ~3 atm. The main features of the spectra correspond to rotational transitions in the ground vibrational state of the complex, i.e., resolved T and N lines (Δl = ± 3) and unresolved R and P lines (Δl = ± 1), where l is the rotational quantum number of the complex. The spectra are analyzed with eigenvalues derived from the wave-mechanical solution of the isotropic Lennard–Jones 12–6 potential with constants determined from the combination rules for mixed molecular species. Although there is good overall agreement, it is evident that finer details of the spectra will require the introduction of an anisotropic intermolecular potential for their explanation.

Spectra of (H2)2, (D2)2, and H2–D2 Van der Waals Complexes

1974 ◽  
Vol 52 (12) ◽  
pp. 1082-1089 ◽  
Author(s):  
A. R. W. McKellar ◽  
H. L. Welsh
Keyword(s):  
Fine Structure ◽  
Nuclear Spin ◽  
Selection Rule ◽  
Van Der Waals ◽  
Rotational Quantum Number ◽  
Van Der Waals Complexes ◽  
Not Given ◽  
Simple Effect ◽  
Anisotropic Force ◽  
Nuclear Spin Statistics

Spectra due to the Van der Waals complex (H2)2 have been obtained with greatly improved resolution, and analogous spectra of (D2)2 and H2–D2 have been observed. The experiments were conducted with an absorption path of 110 m in a multiple traversal cell at temperatures between 16 and 21 K. The spectra are manifested as fine structure accompanying the single and double H2 (or D2) transitions in the hydrogen (or deuterium) collision induced fundamental band. The observed structure for (H2)2 and H2–D2 can be unambiguously assigned to rotational transitions of the complex governed by the selection rule Δl = ± 1, ± 3, where l is the rotational quantum number of the complex. A detailed analysis must include anisotropic force effects, and is not given here. The spectrum of (D2)2 is complicated, not only by anisotropic force effects, but also by mutual perturbations between the rotational levels of the upper states of corresponding single and double D2 transitions; for this reason, the assignments suggested are somewhat uncertain. An interesting intensity alternation apparent in part of the (D2)2 spectrum is explained as a simple effect of nuclear spin statistics in the pseudodiatomic molecule (D2)2.

High-resolution spectroscopy of 4-fluorostyrene-rare gas van der Waals complexes: Results and comparison with theoretical calculations

1998 ◽  
Vol 108 (5) ◽  
pp. 1836-1850 ◽  
Author(s):  
N. M. Lakin ◽  
G. Pietraperzia ◽  
M. Becucci ◽  
E. Castellucci ◽  
M. Coreno ◽  
...  
Keyword(s):  
High Resolution ◽  
Theoretical Calculations ◽  
Van Der Waals ◽  
Van Der Waals Complexes ◽  
High Resolution Spectroscopy ◽  
Rare Gas

CALCULATION OF THE SELF-BROADENING OF RAMAN LINES DUE TO DIPOLAR AND QUADRUPOLAR FORCES

1963 ◽  
Vol 41 (3) ◽  
pp. 433-449 ◽  
Author(s):  
J. Van Kranendonk
Keyword(s):  
Phase Shift ◽  
Cross Sections ◽  
Scattered Light ◽  
Rotational Quantum Number ◽  
Intermolecular Forces ◽  
Intermolecular Potential ◽  
Radiation Process ◽  
Impact Theory ◽  
Order Of Magnitude ◽  
The Impact

The impact theory of Raman line broadening due to anisotropic intermolecular forces, developed previously, is applied to the broadening due to dipolar and quadrupolar forces. The optical cross sections are calculated assuming the isotropic intermolecular potential to be a hard-sphere potential, and neglecting the spread in velocities. Explicit expressions are derived for the phase-shift contribution to the width of the isotropic (j = 0) and anisotropic (j = 2) Raman scattered light as a function of the rotational quantum number J. For j = 2 scattering the phase shifts produced in the radiation do not vanish when the initial and final states of the radiation process are identical, and the phase-shift contribution to the width of the anisotropic components of the Q lines is of the same order of magnitude as for the S lines. In all cases the phase-shift contribution tends to zero when J becomes large compared with j. The contribution to the width of the inelastic collisions also tends to zero for large J, but this is characteristic of the long-range interactions considered here and results from the correspondingly short range of the resonance factors. The theory is compared with the available experimental data on H2 and N2. It is pointed out that quite generally an observation of the broadening of the isotropic and anisotropic Raman lines allows a determination of the lifetimes of the rotational levels and of the phase-shift contributions to the width of the anisotropic lines.

Resonant two‐photon ionization of fluorene rare‐gas van der Waals complexes

1983 ◽  
Vol 79 (12) ◽  
pp. 5769-5779 ◽  
Author(s):  
Samuel Leutwyler ◽  
Uzi Even ◽  
Joshua Jortner
Keyword(s):  
Van Der Waals ◽  
Van Der Waals Complexes ◽  
Rare Gas ◽  
Two Photon ◽  
Photon Ionization

Absorption spectra of small niobium and gold clusters measured by photodepletion of their rare gas van der Waals complexes: some preliminary experiments

1993 ◽  
Vol 26 (1-4) ◽  
pp. 36-40 ◽  
Author(s):  
B. A. Collings ◽  
K. Athanassenas ◽  
D. M. Rayner ◽  
P. A. Hackett
Keyword(s):  
Absorption Spectra ◽  
Van Der Waals ◽  
Gold Clusters ◽  
Van Der Waals Complexes ◽  
Rare Gas
Sign in / Sign up

Export Citation Format

Share Document