Browsing by Subject "Transition metal compounds"
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Item Annulated bis(imidazolium) salts: synthesis, characterization, and applications(2007-12) Boydston, Andrew Jackson, 1978-; Bielawski, Christopher W.; Willson, C. G. (C. Grant), 1939-The design, synthesis, characterization, and applications of annulated bis(imidazolium) salts are described. New synthetic methodologies have been developed that allow access to a broad structural range of bis(imidazolium) salts. Initial studies focused on thee use of bis(imidazolium) salts as comonomers in the formation of mainchain organometallic polymers. Two distinct polymer scaffolds were synthesized, one featuring metal(II)dihalides in the main-chain, and the other featuring a chelated metal center. Ultimately, polymerizations were conducted under ambient atmosphere, proceeded in excellent overall yield, and provided main-chain organometallic polymers comprising Ni(II), Pd(II), and Pt(II) with molecular weights up to 106 Da. Departing polymer studies, focus was shifted toward the study of the physical and photophysical properties of the bis(imidazolium) salts. In few synthetic manipulations, a series of highly photoluminescent bis(imidazolium) salts were prepared whose substituents enable emission in solution, in the solid-state, and, uniquely, as free-flowing liquids. Importantly, these materials display excellent physical properties, such as low glass-transition temperatures (< 0 °C) and high thermal stabilities (> 300 °C). In addition, the bis(imidazolium) platform enabled access to two new fluorescent ionic liquid crystals, demonstrating an ability to also control mesomorphic properties of these materials. Further investigations were conducted regarding the photophysical properties of bis(imidazolium) salts. Focus was placed upon absorption and emission wavelength tunability, solvatochromism, red-edge excitation, and chemical stability. Through functional group modulation, the [lambda]em were varied from 329 -- 561 nm with [Phi]fs up to 0.91. Both the absorption and emission characteristics were found to display strong solventdependencies which were found to be strongly influenced by the nature of the bis(imidazolium) core. The red-edge effect was investigated for a series of bis(imidazolium) salts and was found to be similar between Br and BF4 salts, but distinctly different when MeSO4 anions were incorporated. The stability of an amphiphilic BBI was quantified in aqueous solutions of varying pH and > 85% of the emission intensity was retained after 2 h at pH levels of 3 -- 9.Item Contributions to the chemistry of the group V-group V bond(Texas Tech University, 1982-12) Avens, Larry RossNot availableItem Electrochemical investigations of the reactions of nickel phenanthroline derivatives with alkyl bromides and activated olefins(Texas Tech University, 1982-05) Kuo, Yang-mingNot availableItem Electrochemical synthesis of organometallic nickel compounds with chemical applications(Texas Tech University, 1982-12) Lyster, Thomas HNot availableItem New metal-assisted synthesis of functionalized olefins(Texas Tech University, 2003-08) Karur, SubramanianThis thesis describes new methodologies for the synthesis of â-substituted Baylis- Hillman and related adducts using stoichiometric amounts of Lewis acids, titanium tetrachloride and diethylaluminum iodide. The first palladium-catalyzed addition of N,N-dichlorosulfonamides to internal alkynes is also described. The TiCl4-mediated conjugate addition of halide anions to ethyl vinyl ketone and subsequent trapping of the titanium enolate with aldehydes resulted in p-halo aldol products with syn/anti selectivity up to 8.4/1.0. These halo aldol products can be converted to the corresponding Baylis-Hillman adducts by the treatment with tertiary amines. The EtiAlI-promoted Baylis-Hillman reaction of a.p-unsaturated 5-lactones is achieved for the first time. The Baylis-Hillman adducts are obtained in 50-73% chemical yields. Electron-donating aldehydes required higher temperature and gave lower yields compared to electron-withdrawing aldehydes. The first palladium acetate catalyzed aminohalogenation of internal alkynes with N,N-dichlorosulfonamides gave haloamine functionalized alkenes. The resulting enamides can serve as important versatile building blocks for organic synthesis.Item Preparation and reactions of transition metal-indium mixed metal complexes(Texas Tech University, 1992-08) Lin, Chu-chiehThe primary objective of this research is the syntheses of new complexes containing bonds between transition metals and indium. The secondary objective is to synthesize new compounds containing copper, indium and selenium. A number of transition metal-indium mixed-metal complexes have been synthesized. Their structures have been characterized by single crystal X-ray diffraction as well as other spectroscopic methods. Several compounds containing copper, indium and selenium were also synthesized and characterized. Fe3(CO)l2 reacted with InCl to give |(CO)4Fe(M- InCl(THF))|2 (1) which further reacted with In-Bu)4NBr producing |(n-Bu)4N]2l(CO)4Fe(|Li-InClBr)j2 (2). Fe(C0)4(THF) is believed to be the intermediate in the preparation of compound (1) in all of the following reactions: Fe3(CO)i2 + InCL Na2Fe(CO)4 + InCl3 and Na2Fe2(CO)8 + InCl3. The reaction of |{C0)4Fe{ M-lnCI(THF) 1|2 with NaOR (NaOR: sodium 2.4,6-Tri-ieri-hutyl phenoxide) furnished an uncharacterized compound (3) which further reacted with Ph4PBr to yield |PPh4 l2l(CO)4Fe{)Li-lnCIBr) |2 (4). The reaction of Co4(CO)|2 with InBr in THE at room temperature formed | {(CO)4Co } 2lnm-Br) |2 (5) and |(CO)i2Co4lnKBri2i (6). Co4(CO)l2 reacted with InCI to give |((CO)4Co)2ln(|i-CI)|2 (7) and f(CO)i2Co4ln8Cli2l (8). The reaction of compound (5) with PPh3 gave l{(PPh3)Co(CO)3}InBr2(PPh3)] (9) and [ ((PPh3)Co(CO)3 )2ln(|Li Br)J2 (10). Compound (6) reacted with AsPh3 to give |{(AsPh3)Co(CO)3)InBr2(AsPh3)] (11). The reaction of compound (7) with BzEt3NCl produced IBzEt3Nl2l(CO)i2Co4ln8Cli4(CH3CN)4](12). Ru3(CO)i2 reacted with InCl to yield a cluster which was characterized as |Ru(C0)2ln(THF)|n (where, n > 4) (13) which further reacted with BzEt3NCI to give |Ru(CO)2lnCI(BzEt3N)|n (14). The reaction of (i-Bu)SeSe(t-Bu) with |(C0D)CuCI)|2 produced |( t-Bu )SeSe(t-Bu )(CuCI )2 In (15). (i-Bu)2Se reacted with |(C0D)CuCI)2 to yield a colorless compound which was characterized as | {(t-Bu)2Se }2CuCI |2 (16).Item Reactions of electrophiles with transition metal carbonyl anions(Texas Tech University, 2002-08) Park, Eun JungThe chemistry of compounds containing metal-metal bonds has attracted many inorganic chemists' interest. This research is based on reactions between metal carbonyl anions (Na2Fe(CO)4, Na2Cr(CO)5, and KFe(ç^5-C5H5)(CO)2) and transition metal halides in an attempt to make polynuclear metal cluster compounds via salt elimination reactions. Except metal-metal compound synthesis in the reaction between metal carbonyl anion and metal halides, oxidation and reduction is also a reaction of importance in chemistry. As it devised to make a metal-metal bonded compound, it shows few trace of the metal-metal compound. After initial metal-metal bond formation, products mainly proceed to characteristic of red-ox reactions by electron transfer. Between the acceptor (metal halide cation) and donor (metal carbonyl anion) metal of intermediate mixed metals, rapid electron transfer occurs by the condition depending on the reactant and environment.Item Spectral, electrochemical and reactivity studies of polynuclear chromium complexes(Texas Tech University, 1984-12) Johnston, Randy ForrestNot availableItem Transition metal compounds of ethyl 2-pyridyl ketoxime and n-propyl 2-pyridyl ketoxime(Texas Tech University, 1963-08) Johnston, Theron ScottNot availableItem Transition metal compounds of n-butyl-2-pyridyl ketoxime and n-pentyl-2-pyridyl ketoxime(Texas Tech University, 1963-06) Lieberman, Kenneth W.Not available