Made available in DSpace on 2014-10-09T12:36:42Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:08Z (GMT). No. of bitstreams: 1 04228.pdf: 1369368 bytes, checksum: 9359a42d983a5041a2b1e9d46808ee7d (MD5) / Dissertacao (Mestrado) - IPEN / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

We measure inelastic cross sections for atomic thorium (Th) and molecular thorium monoxide (ThO) in collisions with $^3$He at temperatures near 1 K. We determine the Zeeman relaxation cross section for Th ($^3$F$_2$) to be $\sim 2 \times 10^{-17}$~cm$^{-2}$ at 800~mK. We study electronic inelastic processes in Th ($^3$P$_0$) and find no quenching even after $10^6$ collisions at 800~mK. We measure the vibrational quenching cross section for ThO~(X,~$\nu=1$) to be $(7.9 \pm 2.7) \times 10^{-19}$~cm$^{-2}$ at 800~mK. Finally, we observe indirect evidence for ThO (X, $\nu=0$)--$^3$He van der Waals complex formation, and measure the 3-body recombination rate constant to be $\Gamma_3 = (8 \pm 2) \times 10^{-33}$~cm$^6$s$^{-1}$ at 2.4~K. The stability of the ground Th ($^3$F$_2$) state, metastable Th ($^3$P$_0$) state, and vibrational excited ThO (X, $\nu=1$) state provides data on anisotropic interactions in new systems and opens up the possibility for further studies and experiments, including trapping. / Physics

No description available.

Investigations into the Physical Properties and Reactivity of Thorium(III) Complexes: A thesis submitted to The University of Manchester for the degree of Doctor of Philosophy in the Faculty of Science and Engineering. Since the first full structural characterisation of a thorium(III) complex 30 years ago, the chemistry of the highly reactive oxidation state has been largely neglected with respect to related uranium(III) chemistry. Despite the employment of nuclear technologies across the globe since the 1950's, the relatively poor understanding of the actinides is somewhat surprising, in particular the models used to describe their bonding. Herein, this work presents an investigation into the reactivity of a thorium(III) complex, [Th(Cp'')3] (Cp'' = {C5H3(SiMe3)2-1,3}-); the synthesis and full characterisation of a new thorium(III) complex, [Th(Cptt)3] (Cptt = {C5H3(tBu)2-1,3}-); and the synthesis of two new hexadentate trisanilido ligands which are shown to stabilise uranium(III) and offer highly flexible coordination modes. All of the compounds presented were characterised via a range of analytical and spectroscopic techniques. [Th(Cptt)3] is shown to react with a series of small molecules, displaying elevated reactivity in the majority of cases to the similar uranium(III) complexes. In this work, [Th(Cptt)3] is shown to activate: P4, pyridine, 4,4'-bipyridine, Ph2CO, MeCN, CS2 and CO2, to form dimeric thorium(IV) complexes. The reactivity studies presented provide the first real measure of the reductive capability of the thorium(III) oxidation state. The first pulsed EPR spectroscopy experiments on actinide containing complexes are reported for a pair of new complexes, [M(Cptt)3] (M = U, Th), with the results allowing the direct calculation, via measurement of hyperfine coupling constants, of bonding between the actinide elements and the supporting ligand framework. The results indicate that comparative covalent character is found for the studied actinide complexes with the only other f-element complex characterised by this technique, [Yb(Cp)3], challenging conventional bonding models.

No description available.

Typescript (photocopy) / x, 319 leaves : ill. (part col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics, 1982

Thesis (Ph.D.) -- University of Adelaide, Dept of Physics, 1982. / Typescript (photocopy).

Thesis (Ph. D.)--University of Chicago, 1932. / Lithoprinted. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." Bibliography: p. 18-20.

L. Gordon's Thesis--University of Michigan. / Two articles, by H.H. Willard and L. Gordon, reprinted from Analytical chemistry, vo. 20, p. 165, Feb. 1948 and v. 25, p. 170, Jan. 1953. Includes bibliographical references.

Th.--Sci.--Nancy--I.N.P.L., 1975. N°: C.N.R.S. AO 10921.