Go to  Advanced Search

Optical spectroscopy of some simple free radicals

Show full item record

Files in this item

Files Size Format Description   View
UBC_1982_A1 C49.pdf 15.31Mb Adobe Portable Document Format   View/Open
 
Title: Optical spectroscopy of some simple free radicals
Author: Cheung, Allan Shi-Chung
Degree Doctor of Philosophy - PhD
Program Chemistry
Copyright Date: 1981
Subject Keywords Radicals (Chemistry) -- Spectra
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.
URI: http://hdl.handle.net/2429/23433
Series/Report no. UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/]
Scholarly Level: Graduate

This item appears in the following Collection(s)

Show full item record

All items in cIRcle are protected by copyright, with all rights reserved.

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893