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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Aluminium alkyls in low-temperature matrices

Kvisle, Steinar. January 1900 (has links)
Thesis (doctoral)--Universitetet i Oslo, 1983. / "Mars 1983." Includes bibliographical references.
2

Reactions and Photochemistry of Transition Metals with Methanol, Water, Hydrogen, and Carbon Monoxide via FTIR Matrix Isolation Spectroscopy

January 1988 (has links)
The reactions and photochemistry of atomic and diatomic transition metals with methanol, water, hydrogen, and carbon monoxide in noble gas matrices at cryogenic temperatures have been studied with the use of Fourier Transform infrared inert matrix spectroscopy. Atoms and dimers of iron and cobalt reacted with methanol to form the adducts, M(CH30H) and M2(CH30H), respectively. M(CH30H) underwent metal insertion into the 0-H bond of methanol to yield methoxymetal hydride, CH3OMH, with irradiation of the matrix in the violet (400 nm < λ < 500 nm) region. Ultraviolet (280 nm < λ < 360 nm) photolysis of the matrix rearranged CH30MH to yield the methylmetal hydroxide species, CH3MOH. CH30MH dissociated into carbon monoxide and hydrogen after prolonged irradiation in the ultraviolet region. Surprisingly, nickel atoms reacted spontaneously to insert into the 0-H bonds of methanol and water to form CH30NiH and HONiH, respectively. Violet photolysis caused CH30NiH to rearrange to form methylnickel hydroxide, CH3NiOH. This is effectively a two step process of the C-0 activation of methanol by a nickel atom. In addition to rearrangement, CH30NiH dissociates into carbon monoxide and hydrogen with violet photolysis. Nickel dimers also reacted spontaneously with water to form both an adduct and insertion products. Atomic nickel spontaneously inserts into the H-H bond of molecular hydrogen to yield a bent nickel dihydride, NiH2, in krypton and xenon matrices. Nickel dimers and trimers insert into the H-H bond of hydrogen to form Nix(H)2. In addition to the insertion products, nickel atoms, dimers, and trimers form adducts molecularly with hydrogen to yield complexes of the form Nix(H2)y, where x or y = 1-3. Reactions of iron with carbon monoxide in an argon matrix yielded the iron-carbonyl complexes, Fex(CO)y, where x = 1-3 and y = 1-2.
3

Vibrational spectroscopic studies of matrix isolated molecules

Evans, Richard January 1980 (has links)
The Raman spectrum of polycrystalline or matrix-isolated S<sub>2</sub>N<sub>2</sub> shows three bands attributable to its Raman active fundamentals, including two in close proximity; the possibility of Fermi resonance is discounted. The infrared spectrum.of polycrystalline S<sub>2</sub>N<sub>2</sub> shows five bands, including three attributable to the infrared active fundamentals, while the others are associated with some intermediate species in the polymerisation of S<sub>2</sub>N<sub>2</sub>. The vibrational spectra of matrix-isolated S<sub>4</sub>N<sub>4</sub> are consistent with previous observations in the solid state and in solution, also with the established cage structure of the molecule. The stretching force constants of S<sub>2</sub>N<sub>2</sub> and S<sub>4</sub>N<sub>4</sub>, lower than those predicted on the basis of observations on acyclic S-N molecules, are correlated with the strain in the molecules and their associated thermodynamic instability. The interaction force constants indicate delocalised π-bonding, apparently more extensive in S<sub>2</sub>N<sub>2</sub>. Substantial cross-ring S-S bonding is evident in S<sub>4</sub>N<sub>4</sub>; S-S interactions in S<sub>2</sub>N<sub>2</sub> are apparently non-bonded and repulsive in nature. The infrared spectrum of matrix-isolated Cr0C1<sub>3</sub> contains bands attributable to the fundamentals of this molecule, along with several indicating the presence of Cr0<sub>2</sub>C1<sub>2</sub> and possibly other related molecules. The Raman spectrum shows just three strong bands, all below 250 cm<sup>-1</sup>, assumed to arise from the deformation fundamentals of Cr0C1<sub>3</sub>; the form of the spectrum is attributed to absorption or fluorescence. The force constants derived for Cr0C1<sub>3</sub> correspond closely to their counterparts in V0C1<sub>3</sub> and Cr0<sub>2</sub>C1<sub>2</sub>, suggesting similar force fields in the three molecules. The infrared spectrum of the volatile products of the reaction between PC1<sub>3</sub> and NaN<sub>3</sub> indicates the presence of several molecules, possibly including C1<sub>2</sub>PN<sub>3</sub> and oligomers of C1<sub>2</sub> P = N, although no definite conclusions are drawn. Spectroscopic evidence also suggests that the reaction between (CH<sub>3</sub>)<sub>2</sub>PC1 and NaN<sub>3</sub> yields (CH<sub>3</sub>)<sub>2</sub>PN<sub>3</sub> as a major product, although observations such as the effect of ultraviolet photolysis remain unexplained.
4

Laboratory studies of astrophysical molecules

Wang, Haiyan. January 2005 (has links)
Thesis (Ph. D.)--University of Florida, 2005. / Title from title page of source document. Document formatted into pages; contains 189 pages. Includes vita. Includes bibliographical references.
5

Atom versus cluster reactivities for calcium and magnesium

Whetten, Alan Ray. January 1984 (has links)
Call number: LD2668 .T4 1984 W53 / Master of Science
6

Improvement and investigation of sample preparation for matrix-assisted laser desorption/ionization of proteins /

Hsiang, Fan, January 1997 (has links)
Thesis (Ph. D.)--Memorial University of Newfoundland, 1997. / Bibliography: leaves 104-113.
7

Matrix isolation studies of reactions of atomic oxygen

Sun, Kwo-Tai Richard 01 January 1979 (has links) (PDF)
The research reported here deals with a study of the reaction of atomic oxygen in the first excited electronic state with hexafluoroacetone (HFA). Matrix Isolation (MI) Spectroscopy was used to elucidate the reaction.
8

Spectroscopic identification of complex species containing water and ammonia and their importance to icy outer solar system bodies

Ennis, Courtney January 2009 (has links)
[Truncated abstract] This thesis examines the bonding interactions and chemical processes associated with irradiated water (H2O) and ammonia (NH3) molecules. The experiments conducted in the present study are designed to replicate the surface chemistry of outer Solar System bodies, particularly the icy surfaces of Saturn's inner moons. Infrared (IR) spectroscopy is used to identify the H2ONH3 complex isolated in an argon (Ar) matrix. An electric discharge is then applied to the H2O and NH3 species to produce the hydroxyl-ammonia (OHNH3) complex and the water-amidogen (H2ONH2) complex. Finally, the ammonia-oxygen (NH3O2) complex is formed in an Ar matrix, complementing previous studies performed by the Quickenden research group, which investigated the conversion of OH radicals into molecular O2 on icy planetary surfaces. ... An electric discharge is applied to the NH3 in Ar mixture, producing the NH2 radical subunit of the complex. Two absorption bands are assigned to the H2O subunit vibrational frequencies of the complex; at 1616.1 cm-1 for the ¿2 HOH bending fundamental and at 3532.1 cm-1 for the ¿1 OH bonded stretching fundamental. Two absorption bands are also assigned to the NH2 radical subunit vibrational frequencies of the complex; at 1498.5 cm-1 for the ¿2 HNH bending fundamental and at 3260.8 cm-1 for the ¿3 NH asymmetric stretching fundamental. These assignments are verified by the isotope substitution method, involving the formation of the deuterated D2OND2 complex analogue in an Ar matrix and the measurement of the isotope induced shifts in peak position in the IR region. The isotopic shifts displayed by the IR absorption bands are in good agreement with the theoretically calculated shifts in vibration frequency when going from the H2ONH2 complex fundamentals to the D2OND2 complex fundamentals. The theoretical calculations also derived an interaction energy of 5.2 kcal mol-1 for the HOHNH2 structure of the H2ONH2 complex. This HOHNH2 structure is also confirmed as the preferred structure of the H2ONH2 complex in the IR experiments, by the observation of a large shift in position of the absorption band associated with the H2O subunit ¿1 OH stretching fundamental, away from the position of the H2O monomer ¿1 OH stretching fundamental. This indicates that the H2O subunit donates a hydrogen for the complex bond in the HOHNH2 complex. The NH3O2 complex is identified in solid Ar matrices at 10.5 K by IR analysis. The NH3O2 complex is formed by the co-deposition of gaseous NH3 in Ar mixtures with O2 in Ar gas mixtures. An absorption band is assigned to the ¿1 OO stretching fundamental for the O2 subunit of the NH3O2 complex at 1552.0 cm-1. This assignment is verified by the isotope substitution method, involving the formation of the deuterated ND3O2 complex analogue in an Ar matrix and the measurement of the isotope induced shift in peak position in the IR region. The isotopic shift displayed by the IR absorption band is in good agreement with the theoretically calculated shift in vibration frequency when going from the NH3O2 complex fundamental to the ND3O2 complex fundamental. The theoretical calculations also derived an interaction energy of 0.28 kcal mol-1 for the NH3O2 complex.

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