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Optical spectroscopy of some simple free radicals Cheung, Allan Shi-Chung
Abstract
This thesis reports studies of the electronic spectra of some gaseous oxide molecules. The (0,0) band of the C⁴ Σ⁻ - X⁴ Σ⁻ electronic transition of V0 has been recorded by intermodulated laser-induced fluorescence at a resolution of about 100 MHz over the range 17300 - 17427 cm⁻¹. The hyper- fine structure caused by the ⁵¹V nucleus (I = 7/2) is almost completely resolved. Internal hyperfine perturbations between the F₂ and F₃ electron spin components (where N = J – ½ and J + ½ , respectively) occur in both electronic states; these are caused by hyperfine matrix elements of the type ΔJ = ±1. The C⁴ Σ⁻ state has many local electronic-rotational perturbations, and also suffers from large spin-orbit perturbations by distant electronic states, for which it has been necessary to introduce a second spin-rotation parameter, Y[sub=s], and the corresponding isotropic hyperfine parameter, b[sub=s]. The background theory for this new hyperfine parameter and the calculation of its matrix elements are described. The A⁴π – X⁴ Σ⁻ electronic transition of V0 in the near infra-red has been recorded at Doppler-limited resolution by Fourier transform spectroscopy, and rotational analyses performed for the (0,0) band at 1.5μ and the (0,1) band in 1.18 μ. The hyperfine structure is prominent in the A⁴π ⁴n[sub=5/2] – x⁴ Σ⁻ subband, and in many of the spin satellite branches. As shown by the value of the Fermi contact hyperfine parameter in the A⁴π its electron configuration is (4sσ)¹ (3dδ)¹ (4pπ)¹ in the single configuration approximation. Laser-induced fluorescence spectra of gaseous FeO have proved that the bands whose P and R branches have been analysed rotationally by Harris and Barrow (and which are known to involve the ground state) are Ω'= 4 – Ω''= 4 transitions. The electron configuration (4sσ)¹ (3dδ)³ (3dπ)² ⁵ Δ[sub=i], is the only reasonable assignment for the ground state of FeO. The rotational structure of the 000-000 band of the 2490 Å system of ¹⁵N0₂ (2²B₂ - X²A₁) has been analysed from high dispersion grating spectrograph plates. The band is found to be slightly predissociated, exactly as in the ¹⁴N0₂ isotope, which suggests that it might be usable for laser separation of the isotopes of nitrogen.
Item Metadata
Title |
Optical spectroscopy of some simple free radicals
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1981
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Description |
This thesis reports studies of the electronic spectra of some gaseous
oxide molecules. The (0,0) band of the C⁴ Σ⁻ - X⁴ Σ⁻ electronic transition
of V0 has been recorded by intermodulated laser-induced fluorescence at a
resolution of about 100 MHz over the range 17300 - 17427 cm⁻¹. The hyper-
fine structure caused by the ⁵¹V nucleus (I = 7/2) is almost completely resolved. Internal hyperfine perturbations between the F₂ and F₃ electron
spin components (where N = J – ½ and J + ½ , respectively) occur in both electronic states; these are caused by hyperfine matrix elements of the type ΔJ = ±1. The C⁴ Σ⁻ state has many local electronic-rotational perturbations, and also suffers from large spin-orbit perturbations by distant electronic states, for which it has been necessary to introduce a second spin-rotation parameter, Y[sub=s], and the corresponding isotropic hyperfine parameter, b[sub=s]. The background theory for this new hyperfine
parameter and the calculation of its matrix elements are described.
The A⁴π – X⁴ Σ⁻ electronic transition of V0 in the near infra-red has been recorded at Doppler-limited resolution by Fourier transform spectroscopy,
and rotational analyses performed for the (0,0) band at 1.5μ and
the (0,1) band in 1.18 μ. The hyperfine structure is prominent in the A⁴π
⁴n[sub=5/2] – x⁴ Σ⁻ subband, and in many of the spin satellite branches. As
shown by the value of the Fermi contact hyperfine parameter in the A⁴π its electron configuration is (4sσ)¹ (3dδ)¹ (4pπ)¹ in the single configuration
approximation.
Laser-induced fluorescence spectra of gaseous FeO have proved that the bands whose P and R branches have been analysed rotationally by Harris and Barrow (and which are known to involve the ground state) are Ω'= 4 – Ω''= 4 transitions. The electron configuration (4sσ)¹ (3dδ)³ (3dπ)² ⁵ Δ[sub=i], is the only reasonable assignment for the ground state of FeO.
The rotational structure of the 000-000 band of the 2490 Å system of ¹⁵N0₂ (2²B₂ - X²A₁) has been analysed from high dispersion grating spectrograph plates. The band is found to be slightly predissociated, exactly as in the ¹⁴N0₂ isotope, which suggests that it might be usable for laser separation of the isotopes of nitrogen.
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Genre | |
Type | |
Language |
eng
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Date Available |
2010-04-13
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0060683
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.