Dissertations / Theses: 'Boron compounds'

1

Brain, Paul Terence. "Studies of some compounds containing boron-boron bonds." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.291091.

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DeGraffenreid, Allison Lynne. "Studies on boron - nitrogen and boron - gadolinium compounds." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1294835746.

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3

Taher, Mamoun. "Novel boron compounds in lubrication." Licentiate thesis, Luleå tekniska universitet, Industriell miljö- och processteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25920.

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Lubricants are used to control friction and reduce wear by preventing direct contact between surfaces in a relative motion. Most of the modern lubricants and lubricant additives have been designed and optimized for ferrous materials. A growing trend towards wider use of lightweight and wear resistant non-ferrous materials calls for new efficient and environmentally friendly Lubricants. Boron compounds are attractive alternatives for the commercially available lubricants and lubricant additives. Some boron compounds have already been proven as efficient friction modifiers, antioxidants, corrosion inhibitors and antiwear additives in lubricants.In this work we focus on design, synthesis, physicochemical characterization and tribological studies of novel boron compounds. Boron based ionic liquids (ILs) and dithiocarbamates (B-DTCs) were designed, synthesized and tribologically characterized. The work was carried out in the following steps: (i) design and synthesis of novel boron compounds; (ii) physicochemical characterization of the synthesized compounds by FTIR, liquid-state (1H, 13C, and 11B) and solid-state (13C and 11B) nuclear magnetic resonance (NMR) spectroscopy, elemental analysis, thermal analysis (TG, DTA, DSC and QMS), powder XRD, density and viscosity measurements; (iii) tribological characterization using four-ball and pin-on-disc tribometers and (iv) surface analysis using Scanning Electron Microscopy coupled with X-ray Energy Dispersive Spectroscopy (SEM/EDS), optical interferometer and stylus profilometer. Some of these new boron-based compounds revealed significantly better antiwear and friction reducing performance on steel-steel contacts compared with fully formulated engine oils. (i) Nine novel ILs of pryrrolidinium bis(salicylato)borate were synthesized and physicochemically characterized. They are solid at room temperature and some of them behave as plastic crystals. Some of these ILs were tested as lubricants at 100 ºC, i.e. above their melting points. These ILs have shown significantly better antiwear and friction reducing performance in lubrication of steel-steel contacts compared to fully formulated synthetic engine oil 5W40.(ii) Nine novel room temperature ionic liquids (RTILs) of pyrrolidinium bis(mandelato)borate were synthesized and physicochemically characterized. These ILs were tribologically tested as 3 wt % additives in polyethylene glycol (PEG) and they have shown considerably better antiwear and friction reducing properties in boundary lubrication of steel-steel contacts at room temperature compared with neat PEG and engine oil 5W40.(iii) Boron based compounds containing alkylborate and dithiocarbamate groups with alkyl substitutes in one molecule were synthesized and physicochemically characterized. The influence of alkyl chain length (butyl and/or octyl substitutes at DTC and borate groups) and heterocyclicity in boron based dithiocarbamate compounds (B-DTCs) on their tribophysical properties as additives in a mineral oil was studied for steel-steel lubricated contacts.
Godkänd; 2012; 20121123 (mamtah); LICENTIATSEMINARIUM Ämne: Gränsytors kemi/Chemistry of Interfaces Examinator: Professor Oleg N. Antzutkin, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Professor Mark Rutland, Chalmers tekniska högskola, Göteborg Tid: Onsdag den 19 december 2012 kl 10.15 Plats: C305, Luleå tekniska universitet

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4

Cui, Jian. "Synthesis and characterization of new boron-nitrogen and boron-nitrogen-phosphorus systems." [Fort Worth, Tex.] : Texas Christian University, 2009. http://etd.tcu.edu/etdfiles/available/etd-03162010-123538/unrestricted/Cui.pdf.

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5

Ceberg, Crister. "Pharmacokinetics and biodistribution of boron compounds foundations for boron neutron capture theory /." Lund : Dept. of Radiation Physics, Lund University, 1994. http://books.google.com/books?id=wnhrAAAAMAAJ.

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6

Rusen, Aydin. "Usage Of Boron Compounds In Copper Production." Phd thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615560/index.pdf.

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Copper losses to slag are generally between 0.7-2.3% during the copper matte smelting stage. In this study, the aim was to reduce these losses in the slag phase. For this purpose, usage of some additives (especially calcined colemanite labeled as CC, boric oxide-B2O3 and calcium oxide-CaO as well) as flux material was investigated. The flash furnace matte-slag (FFM-FFS) obtained from Eti Copper Inc. and a master matte-slag (MM-MS) produced synthetically were used as starting materials. Additives were tested in various amounts under two different atmospheres (N2 and low Po2 obtained by mixture of CO2/CO gases). Temperature and duration were also used as experimental variables. Experimental results have indicated that 2 hours was sufficient to obtain a low copper content in slag about 0.3% and 0.4% for FFS and MS, respectively. It was also seen that the copper content in slag decreased with increasing CC addition at all oxygen partial pressures and at all temperatures. Furthermore, the addition of all additives up to 4% had great influence in lowering the copper content in the final slags (~0.3%Cu). From FactSage calculations, it could be concluded that the colemanite addition decreased the liquidus temperature which led to early melting of slag and allowed enough duration for settling of matte particles within the slag without substantial changing its viscosity, which resulted in less mechanical copper losses to the slag. By using colemanite in copper production, it was possible that a new application area for boron compounds which are produced in Turkey could be created.

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El-Kheli, M. N. A. "Sterically hindered organo-boron and -cadmium compounds." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356502.

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8

Breitling, Frank Michael. "Boron-bridged constrained geometry complexes and related compounds." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420881.

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Bull, Andrew E. A. "Synthesis and characterisation of sulfur containing boron compounds." Thesis, University of Bristol, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404434.

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10

Shah, Jungal (Jugal Kaushik). "Hypoxia-selective compounds for boron neutron capture therapy." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44829.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2008.
"June 2008."
Includes bibliographical references.
Boron neutron capture therapy (BNCT) is a biochemically targeted form of radiotherapy for cancer. In BNCT, a compound labeled with the stable isotope boron-10 is systemically administered, and tumor cells selectively uptake the boron-10 containing compound at higher concentrations than normal cells. A general problem with the tumor seeking compounds is that drug delivery is dependent upon sufficient vascularization within the tumor. To investigate the possibility of delivering boron to hypoxic regions of tumor, a new boronated nitroimidazole delivery agent has been synthesized as a carrier of boron-10 for BNCT. It is expected that this will be used in combination with the existing boron carrier boronophenylalanine-fructose to treat solid tumors. An immunohistochemical protocol to visualize hypoxia was tested and refined to confirm the suitability of two tumor models established in the lab for hypoxia related uptake studies. The immunohistochemical protocol is used to detect pimonidazole, which localizes at hypoxic regions in tissue and is the parent compound for the new hypoxia-selective boron carrier. The protocol was used to test and confirm the suitability of a hypoxic in vivo tumor model. Two tumor lines were tested: SCCVII squamous cell carcinoma and EMT-6 murine mammary carcinoma. Both exhibited hypoxia. Finally, quantitative studies using Inductive Coupled Plasma Atomic Emission Spectrum demonstrated that the synthesized boronated nitroimidazole reaches suitable concentrations in SCCVII and F98 tumor. Future therapeutic studies are required to empirically confirm the effectiveness of this compound.
by Jugal Shah.
S.B.

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11

McNab, Donald. "Boron-containing compounds as inhibitors of HIV proteinase." Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/14305.

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HIV Proteinase (HIV PR) has proved to be an excellent target for the development of anti-AIDS drugs. Four inhibitors of this enzyme are now approved for clinical use but they, like others, suffer from shortcomings associated with their size and the fact they are peptides. In this thesis the development of small non-peptidic cyclic compounds is described. They were designed to inhibit HIV PR principally by targeting its unique structural features rather than by mimicking its natural substrates. The designed compounds all contained the borinic acid functional group which it was anticipated would interact with the two critical aspartic acid residues of HIV PR. A heteroatom incorporated into these compounds was positioned in such a way that a water molecule which plays a pivotal role in the binding of the enzyme's substrates was displaced. Finally, two benzyl groups were incorporated; these were designed to mimic the side-chains of phenylalanine and tyrosine frequently found in the substrates of HIV PR. The borinic acid functional group has not previously been incorporated into HIV PR inhibitors. Therefore, an analogous series of five 2,6-dibenzylated-4-heterocyclohexanols, where the borinic acid group had been replaced by a hydroxyl group, were prepared and evaluated against the enzyme. These were prepared through bis aldol condensations followed by reduction of the carbonyl group in the bisenones that resulted from dehydration. Although low solubility prevented the analysis of three of these compounds and thereby their effectiveness, two of them were found to be moderately active. Having validated the design of the heterocyclic template, attempts were then made to synthesise borinic acid-containing analogues of these 4-heterocyclohexanols. The attempted syntheses of a directly comparable series of compounds, through application of both bismetallation and bishydroboration strategies, was unsuccessful. Instead, two acyclic diphenyl borinic acids were synthesised. Additionally, several related cyclic borinic acids and acyclic borinic and boronic acids consistent with the design strategy were prepared, from diphenyl sulfone, 2-bromodiphenyl ether and 2-bromodiphenyl sulfide, through the appropriate lithiated species formed by either lithium-hydrogen or lithium-halogen exchange. During the attempted syntheses of a cyclic borinic acid by selective oxidative cleavage of an organoborane derived from diphenyl sulfone, two highly novel borane-amine adducts were synthesised. None of the boron-containing compounds assayed against HIV PR were found to be inhibitors of the enzyme. This is thought to be as a result of the phenyl groups being directly attached to the boron atom, rather than being present in benzyl substituents as had been originally planned.

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12

Leung, Hoitung Terry. "Chemistry of deca- and dodeca-closo-borate bearing three exopolyhedral sulfur substituents." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1092772114.

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Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xvii, 168 p.; also includes graphics (some col.) Includes bibliographical references (p. 164-168). Available online via OhioLINK's ETD Center

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13

Jones, Charlotte Louise. "Synthesis, characterization and computational studies of boron-oxygen compounds." Thesis, Bangor University, 2016. https://research.bangor.ac.uk/portal/en/theses/synthesis-characterization-and-computational-studies-of-boronoxygen-compounds(8c2d8db8-e5e0-4582-8e4d-2abd5b72fa97).html.

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A total of twenty-one new non-metal cation polyborate salts are reported; nineteen of these contain the pentaborate anion, [B5O6(OH)4]-, one contains the triborate monoanion, [B3O3(OH)4]-, and one contains the heptaborate dianion, [B7O9(OH)5]2-. The crystal structures of ten salts containing these polyborate anions are reported: pyrrolidinium pentaborate (1), N-methylpyrrolidinium pentaborate.½ acetone (2.½CH3COCH3), N,N-dimethylpyrrolidinium pentaborate (3), 2-hydroxymethylpyrrolidinium pentaborate hemihydrate (4.½H2O), (2-hydroxyethyl)-N-methylpyrrolidinium pentaborate.0.3 hydrate (5.0.3H2O), 4-aminobenzylammonium pentaborate hemihydrate (9.½H2O), N,N-dimethyl-1-adamantylammonium pentaborate sesquihydrate (14.1.5H2O), N,N,N-trimethyl-1-adamantylammonium pentaborate trihydrate (15.3H2O), N,N,N-trimethyl-2-adamantylammonium pentaborate trihydrate (17.3H2O) and 4,4’-bipiperidinium heptaborate dihydrate (20.2H2O). The crystal structure of an additional amine-boric acid co-crystallized species is also reported. All of the synthesized compounds reported in Chapter 3 were characterized using spectroscopic (IR, multi-element NMR) and analytical (melting point, elemental analysis, thermal analysis, powder X-ray diffraction) techniques. The solid-state structures of the polyborate salts form giant H-bonded anionic lattices, with the ‘brickwall’ structure found to be sufficiently flexible to accommodate larger cations (within limits). When these limits are approached, they may be stretched further to accommodate the size of the cations by using ‘spacer’ molecules which increase the size of the lattice. It is only once the lattice cannot be stretched any further and/or when there are sufficient cation-anion interactions to dominate the energetics that polyborates other than pentaborates may be observed. The strength of the H-bonds found within polyborate salts were calculated using DFT theory; the results show that the α-reciprocal R22(8) H-bond interaction is the most energetically favoured (-21 kJ mol-1), which is also the most commonly observed interaction within the solid-state structures of pentaborate salts. The synthesis and characterization of Lewis base adducts of triorganoboroxines is also described within this thesis. Eight new adducts are reported, including the crystal structures of the triorganoboroxine.amine adducts of tri(4-chlorophenyl)boroxine.morpholine (30) and tri(4-chlorophenyl)boroxine.benzylamine (33). The Lewis acidity of the triorganoboroxines were also investigated and it was discovered that strongly electron-withdrawing pentafluorophenyl substituents greatly increase the Lewis acidity of the B atoms, resulting in a higher acceptor number.

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14

Perez, Fuertes Yolanda. "New strategies using BINOL-boron compounds for organic synthesis." Thesis, University of Bath, 2005. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414606.

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15

Eltepe, Hüdal Emre Balköse Devrim. "The Development of Zinc Borate Production Process/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/kimyamuh/T000499.pdf.

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16

Wang, Zhiran. "The demagnetising factors for bonded neodymium iron boron (NdFeB) magnets." Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340145.

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17

Van, Duijn Joost. "Powder neutron diffraction studies of some magnetic boron-containing compounds." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620967.

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18

Kwok, Chi-chung. "Functional light-emitting materials of platinum, zinc and boron for organic optoelectronic devices." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B34617693.

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19

Currie, Graeme. "Negative Ion Chemistry of Boron and Carbon Compounds / by Graeme Currie." Title page, contents and abstract only, 1988. http://web4.library.adelaide.edu.au/theses/09PH/09phc9762.pdf.

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20

Mercanti, Elia. "Synthesis and dynamic study of atropisomeric compounds containing boron-carbon bond." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10067/.

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In this thesis we studied the stereodynamic behavior of 1,2-azaborines variously substituted on boron (7a, 7b, 13). Depending on the hindrance of the asymmetric aryl substituent the resulting conformations could be stereolabile or configurationally stable. Through dynamic NMR and lineshape simulation, the energy rotational barriers of the different conformers are obtained. When the barrier is higher than 22-23 kcal/mol stable atropisomers that are fisically separable could be obtained (case of compound 13) and the free activation energy barrier is determinable by kinetic analysis. Absolute configuration of two atropisomers were assigned by comparison between computational calculations and experimental ECD. Isosteric compound 21 is then synthesized in order to compare the rotational barrier around B-Caryl with the one around Cnaphth-Caryl bond.

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21

Tanner, Ruth Marie. "A spectroscopic and computational investigation of unstable boron and sulphur compounds." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0027/MQ51101.pdf.

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22

Shah, Faiz Ullah. "Boron compounds as additives to lubricants : synthesis, characterization and tribological optimization." Licentiate thesis, Luleå : Luleå university of technology, 2009. http://pure.ltu.se/ws/fbspretrieve/3350614.

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23

Zhao, Hailiang. "Computational study of the boron-nitrogen dative bond." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/2846.

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Thesis (MSc (Chemistry and Polymer Science))--Stellenbosch University, 2007.
In this study, ten selected boron-nitrogen compounds and three borane carbonyl complexes were investigated by a number of computational methods. It is well known that the B-N dative bond is shorter in the solid state than in the gas phase. The B-CO distance, on the other hand, displays the opposite effect. Quantum mechanical techniques at the Hartree-Fock, Møller-Plesset second-order and Density Functional Theory level were used to calculate the geometries of the isolated molecules and to compare them with those found in molecular clusters built to model the solid state. It was found that calculated geometries were very sensitive to the choice of the basis set. The effects of dipole-dipole interactions were further investigated by applying an external electric field with varying strength to isolated molecules, and by replacing the central molecule in a cluster with a different compound. The B-N bond was found to respond much more to the applied field than the B-CO bond. An effort was made to correlate the lengthening or shortening of the dative bond to the strength of the crystal field, the latter being calculated classically from point charges. Unfortunately, large differences were noted between the charges calculated with common methods like Mulliken or Merz-Kollman-Singh. Furthermore, an analysis of 67 crystal structures taken from the Cambridge Structural Database did not reveal a correlation between the length of the B-N bond and the crystal field calculated with Charge Equilibration charges. Finally, a valence force field was developed for H3N-BH3. It was shown that a much better fit of the vibrational spectrum can be obtained if the B-N stretching mode is assigned to the 603 cm-1 band rather than the peak observed at 968 cm-1.

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24

郭子中 and Chi-chung Kwok. "Functional light-emitting materials of platinum, zinc and boron for organic optoelectronic devices." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B34617693.

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25

Poon, Chun-ting, and 潘俊廷. "Design and synthesis of boron (III)-containing dithienylethenes--from multi-addressable and gated photochromism to photoswitchable luminescence functions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hdl.handle.net/10722/207983.

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A series of photochromic dithienylethene-containing triarylboranes has been synthesized and characterized. The X-ray crystal structure of (4,5-bis(2,5-dimethylthiophen-3-yl)-thiophen-2-yl)dimesitylborane has been determined. An intense electronic absorption band was observed in all the triarylborane-containing compounds, corresponding to the intramolecular charge-transfer transition from the π-conjugated thiophene / fused thiophene / bithiophene to the vacant pπorbital of boron. This class of compounds was also found to bind fluoride ion such that the trigonal planar geometry of the boron center would be changed to tetrahedral, leading to a significant perturbation in the photophysical properties. Upon photo-excitation into the transition band, (4,5-bis(2,5-dimethylthiophen-3-yl)-thiophen-2-yl)dimesityl- borane and (4,5-bis-(2,5-dimethylthiophen-3-yl)-thieno[3,2-b]thiophen-2-yl)- dimesitylborane displayed multi-addressable photochromic reactivities upon addition of fluoride, in which a green solution was found in the closed form of the unbound compounds, while they changed to a purple color upon fluoride binding. Interestingly, both (4',5'-bis(2,5-dimethyl-thiophen-3-yl)-2,2'- bithiophen-5-yl)dimesitylborane and (4',5'-bis(2,5-dimethyl-thiophen-3-yl)-2,2'- bithiophen-3-yl)dimesitylborane displayed gated photochromic reactivities upon addition of fluoride, while only typical photochromic reactivity was observed in (4',5'-bis(2,5-dimethyl-thiophen-3-yl)-2,2'-bithiophen-4-yl)- dimesitylborane, indicative of a strong influence of the substituent effect on the photochromic reactivity upon incorporation of the -BMes2 group. A series of photochromic dithienylethene-containing β-diketones and the corresponding boron(III) compounds, appended with -BF2, -B(C6F5)2 and -BPh2, have been designed and synthesized. Upon photo-excitation into the transition band, typical photochromism was observed in all the dithienylethene- containing β-diketone ligands with the color changed from pale yellow to green in degassed benzene solution. Upon incorporation of the -BF2 and -B(C6F5)2 groups, near-infrared responsive photochromic behavior was observed, in which the absorption of the closed form was found to be at ca. 758-863 nm, suggesting that a pronounced perturbation of the dithienylethene was achieved by coordination of the boron(III) center. Moreover, a significant reduction in luminescence intensity of over 90 % was observed upon photocyclization, indicative of their potential application as photoswitchable luminescence materials. The thermal stability of the closed form and the activation energy for the thermal cycloreversion have also been studied on the representative compounds, 1-(4,5-bis(2,5-dimethylthiophen-3-yl)thiophen-2- yl)-butane-1,3-dione and difluoroboryl(1-(4,5-bis(2,5-dimethylthiophen-3-yl)- thiophen-2-yl)butane-1,3-dionate). A series of photochromic dithienylethene-containing BODIPY has been successfully prepared and characterized. The electronic absorption properties have been studied. These compounds showed an intense visible absorption band, corresponding to the 0-0 band of a strong S0→S1 transition of the BODIPY core, with a weak and broad absorption band at higher energy, corresponding to the S0→ S2 transition of the BODIPY core. An absorption band in the UV region was also observed in 2,3-bis(2,5-dimethyl- thiophen-3-yl)thiophene-containing derivatives, corresponding to the π→π* transitions of the dithienylethene moiety. The photochromic reactivities have also been studied such that the photostationary state was found to be reached upon irradiation in the UV region for over eight hours, while no observable changes would be obtained upon photo-excitation in the visible region. The slow conversion rate has been suggested to be attributed to the fact that a rapid excitation energy transfer could occur from the excited Th-DTE to the BODIPY moiety, rendering the suppression of the photocyclization.
published_or_final_version
Chemistry
Doctoral
Doctor of Philosophy

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26

Meng, Yan. "Synthesis of organoboron compounds by difunctionalization of alkenes:." Thesis, Boston College, 2020. http://hdl.handle.net/2345/bc-ir:109010.

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Thesis advisor: James Morken
This dissertation details two different alkene difunctionalization strategies that are utilized in the synthesis of three types of organoboron species in racemic and enantioenriched fashion. Chapter one will introduce the carbohydrate and DBU co-catalyzed transition-metal-free enantioselective diboration reactions of unactivated alkenes. Mechanistic insights guided reaction condition design will be discussed. In chapter two, a nickel-catalyzed conjunctive cross-coupling of 9-BBN borane and carboxylic acid derivatives is presented. Its development and detailed mechanistic studies, along with the efforts in asymmetric induction will be covered. Finally, the first enantio- and diastereoselective synthesis of 1,2-anti-silylboronates enabled by palladium-catalyzed conjunctive cross-coupling will be described. The optimization of chemo-, enantio- and diastereoselectivity in the reactions and their following transformations (e.g. oxidation and amination) is demonstrated
Thesis (PhD) — Boston College, 2020
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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27

Jungryang, Kim. "Synthesis, thermal stability and electrochemical behavior of lithium boron nitride intercalation compounds." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225701.

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28

Xie, Zhilin. "Re, Os, Al and Mg boron rich ceramic compounds for structural application." Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5581.

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Hard and ultra-incompressible materials are of great interest due to their important applications in industry. A common route to design hard materials is combining transition metals with light and small covalent elements. Light elements such as carbon, oxygen, nitrogen and boron have been considered as good candidates. This study includes the synthesis of ReB2, OsB2 and another higher boride AlMgB14. Most of the techniques used for ReB2 synthesis reported 1:2.5 Re to B ratio because of the loss of the B during high temperature synthesis. However, as a result of B excess, the amorphous boron, located along the grain boundaries of polycrystalline ReB2, would degrade the ReB2 properties. Therefore, techniques which could allow synthesizing the stoichiometric ReB2 preferably at room temperature are in high demand. This thesis reported the synthesis of ReB2 powders using mechanochemical route by milling elemental crystalline Re and amorphous B powders in the SPEX 8000 high energy ball mill for 80 hours. The formation of boron and perrhenic acids are also reported after ReB2 powder was exposed to the moist air environment for a twelve months period of time. The synthesized ReB2 powder was characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, secondary ion mass spectrometry and Raman spectroscopy. OsB2 also shows its attractive properties. The hardness of orthorhombic OsB2 was reported to be 37 GPa, when the applied load is lowered to 0.245N. However, only one of the three predicted phases has been synthesized. In this study, the hexagonal OsB2 has been synthesized by the mechanochemical method. The lattice parameters of the Hex-OsB2 are α=β=90°, γ=120°; a=b=2.9047 Å, c=7.4500 Å. The synthesized OsB2 powder was annealed at 1050°C for 6 days, but no phase change was found. This shows that the Hex-OsB2 is very stable. Another promising hard material, AlMgB14, was also studied in this thesis. The AlMgB14 was synthesized at 1050 °C under normal pressure. Several different routes were tried and compared. It shows AlMgB14 cannot be synthesized merely by ball milling, which can bring the risk of oxidization. Magnesium metal is preferred to use as one of the raw materials.
ID: 031001456; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Adviser: Nina Orlovskaya.; Co-adviser: Richard G. Blair.; Title from PDF title page (viewed July 3, 2013).; Thesis (M.S.M.E.)--University of Central Florida, 2012.; Includes bibliographical references (p. 66-71).
M.S.M.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering; Mechanical Systems

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29

Mizori, Farhad G. "Transmetallation from zirconium to boron : the synthesis and conjugate addition of mixed unsymmetrical tricoordinate organoboranes containing phenyl and methyl groups /." Diss., Connect to a 24 p. preview or request complete full text in PDF formate. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3138868.

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30

Strickland, Christopher E. "Reactive molecular dynamics force field for simulating hydrogenated boron nitrogen compounds and interactions with silica surfaces." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Fall2007/C_Strickland_110907.pdf.

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31

Hess, Euodia. "Boron-doped Diamond Sensors for the Determination of Organic Compounds in Aqueous Media." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5310_1305022937.

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In electrochemical oxidation treatment of wastewater, the electrode material is an important parameter in optimizing oxidative electrochemical processes, since the mechanism and products of several anodic reactions are known to depend on the anode material. The electrochemical oxidation of benzaldehyde, nitrobenzene and m-cresol on bare boron-doped diamond (BDD) electrode was investigated. Cytochrome c was then electrochemically immobilsed onto the functionalized BDD electrode by cyclic voltammetry. Oxidation and reduction reaction mechanism of each flavonoid was studied. There was one oxidation and reduction peaks for quercitin and catechin respectively, and two oxidation and two reduction peaks for rutin. The cytochrome c modified BDD electrode showed good sensitivity for all three flavonoids and low detection limits i.e. 0.42 to 11.24 M as evaluated at oxidation and reduction peaks, respectively.

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32

Zhu, Xuping 1970. "In vivo boron-10 analysis for the pre-screening of compounds for BNCS." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28366.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2004.
Includes bibliographical references (p. 122-125).
An in vivo boron-10 screening technique was developed to analyze the boron biodistribution in a rabbit knee for the pre-screening of compounds for Boron Neutron Capture Synovectomy (BNCS). Three approaches were investigated: emission computed tomography (ECT), transmission computed tomography (TCT) and in vivo prompt gamma neutron activation analysis (IVPGNAA). Each was first studied using simulation-generated projection data. Experimental data collection systems were then constructed for TCT and IVPGNAA, and phantom experiments were conducted at the MIT Research Reactor (MITR) to verify simulation results. While TCT was predicted to have superior performance in terms of spatial resolution, temporal resolution and boron quantification, IVPGNAA was chosen for further development given the readily available neutron sources at the MITR. Assuming an 8.5x105 cm-2s-1 incident neutron flux, a 3.5mmx20mm beam, and a knee injection of 1.05mg 10B, one projection data set can be collected within 12 minutes, for reconstruction of relative 10B distribution in eight 40mm2 regions. The estimated uncertainty associated with reconstructed results, assuming a regional 2000 ppm concentration, is [approx.] 25%. Phantom experiments demonstrated the overall feasibility of IVPGNAA as a means of conveniently evaluating spatial and temporal characteristics of 10B in a rabbit knee.
(cont.) Animal experiments were then conducted at the MITR using 3.5kg anesthetized arthritic rabbits. Three boronated compounds were investigated, each with widely different in vivo spatial and temporal characteristics, as determined previously via dissection studies. Good agreement in egression behavior between IVPGNAA predictions and dissection study results was found for 2 compounds. The third compound was not detectable under experimental conditions, suggesting the possibility that the compound was not taken up by the synovium. This finding was consistent with the dissection study results. IVPGNAA is an invaluable tool for early rejection of compounds with poor characteristics, and can provide guidance for dissection studies of promising compounds.
by Xuping Zhu.
Ph.D.

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33

Aparece, Mark Docto. "Synthesis of Organoboron Compounds via a Palladium-Induced 1,2-Metallate Shift Mechanism:." Thesis, Boston College, 2020. http://hdl.handle.net/2345/bc-ir:108927.

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Thesis advisor: James P. Morken
This dissertation describes the development of various palladium-catalyzed syntheses of organoboron compounds with the 1,2-metallate shift of organoboron “ate” complexes as a common mechanistic feature. Chapter one discusses the history of the 1,2-metallate shift with a focus on reactions promoted by transition metals, followed by my work on the palladium-catalyzed, enantioselective, halide-tolerant conjunctive cross-coupling reaction to enable the use of Grignard reagents and arylbromides. Chapter two discusses the attempt to engage allylic electrophiles in the conjunctive cross-coupling reaction and the discovery and optimization of the vinylidenation reaction to access 1,1-disubstituted boryl alkenes. Unlike other palladium-catalyzed reactions that proceed by a 1,2-metallate shift, the vinylidenation proceeds by a β-hydride elimination rather than a reductive elimination as the final step in the catalytic cycle. Chapter three discusses the development of the enantioselective conjunctive cross-coupling of propargylic electrophiles to access enantioenriched β-boryl allenes. Methanol additive was found to improve both the yield and enantioselectivity of the reaction. 1H NMR studies show that methanol exchanges with the pinacol ligand on the boron “ate” complex
Thesis (PhD) — Boston College, 2020
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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Coombs, John Ryan. "Platinum-Catalyzed Enantioselective Diboration of Terminal Alkenes and Vinyl Boronates: Construction of Multiborylated Compounds for Asymmetric Synthesis." Thesis, Boston College, 2015. http://hdl.handle.net/2345/bc-ir:104624.

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Thesis advisor: James P. Morken
This dissertation will discuss in depth four main projects pertaining to the synthesis and utility of organoboronates for the construction of enantioenriched small molecules. First, reaction optimization and substrate scope expansion of the platinum-catalyzed enantioselective diboration of alkenes are reported. Based on extensive experimental and computational mechanistic analysis, a preliminary stereochemical model is also proposed. A practical boron-Wittig reaction is presented in which synthetically challenging di- and trisubstituted vinyl boronates can be accessed in a highly stereoselective fashion from readily available starting materials. The enantioselective diboration of cis- and trans-vinyl boronates furnished novel 1,1,2-tris(boronate) esters in up to 95:5 er. The intermediate tris(boronate) esters were employed successfully in deborylative alkylations to furnish enantioenriched internal vicinal bis(boronates) in excellent diasteoselectivity. In the final chapter, an enantioselective palladium-catalyzed intramolecular Suzuki-Miyaura coupling between allyl boronates and aryl electrophiles is disclosed. The newly developed transformation provides enantioenriched 5, 6, and 7-membered carbocycles in up to 93:7 er
Thesis (PhD) — Boston College, 2015
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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35

Rusan, Magdalena. "Investigations of environmentally benign pyrotechnic formulations based on nitrogen-rich and energetic boron-based compounds." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-179187.

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Novel non-toxic and environmentally friendly pyrotechnic formulations have been developed and investigated. A series of nitrogen-rich metal salts and energetic boron-based compounds have been synthesized, characterized and tested as red, green and blue colorants in pyrotechnic compositions.

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36

Bahl, Kushal. "Study of Optimum Process Conditions for Production of Thermally Conductive Polymer Compounds Using Boron Nitride." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1290124133.

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37

Hayes, Roger Nicholas. "A study of some gas phase nucleophilic substitution reactions of carbon, silicon and boron by ion cyclotron resonance mass spectrometry /." Title page, table of contents and summary only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phH418.pdf.

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Todd, Jean Ann. "Platinum(II) complexes containing 1,2- and 1,7-carborane ligands for boron neutron capture therapy." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09pht634.pdf.

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39

Eberlin, Ludovic. "Novel applications of polyfunctionalised organoboron and nitroso compounds." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S078/document.

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Cette thèse présente la réactivité de diènes polyfonctionnalisés incorporant un atome de bore (diènes borylés) en présence de composés de type nitroso. La première partie est une étude de la réactivité des diènes borylés en présence de dérivés arylnitroso. Le produit formé ainsi que l'efficacité de la réaction est dépendant de la substitution sur l'atome de bore ainsi que du solvant utilisé pour la réaction. Suivant les conditions employées, la formation de composés avec différentes structures; pyrroles, oxazines substitués par un atome de bore, ou nitrones a été obtenue. Une stratégie one-pot a ensuite été développée pour la synthèse d'oxazolines utilisant la formation des nitrones en tant qu'intermédiaire. Des investigations théoriques et pratiques concernant le mécanisme de la formation du pyrrole ont été réalisées. La séquence expliquant la synthèse de cette structure est basée sur la cascade suivante; cycloaddition régiosélective (Nitroso Diels-Alder)/réarrangement/élimination du borate. La formation des composés de type nitrone n'a pas été totalement explicité. Des recherches sont actuellement en cours dans le but d'obtenir plus de détails sur le mécanisme mis en jeu. La deuxième partie de l'étude est orientée sur la réactivité des diènes borylés en présence de dérivés carbonylnitroso. Au contraire des dérivés arylnitroso, la nature du composé carbonylnitroso joue un rôle majeur sur la réactivité. Si le même type de réactivité engendrant la formation de pyrroles et d'oxazines substitués par un atome de bore a été observé dans certains cas, l'utilisation d'un composé carbonylnitroso étant assez pauvre en électrons génère la formation du produit issu d'une réaction nitroso-ène. Ce produit, issu de la réaction nitrosoène, a été utilisé comme intermédiaire clé pour la synthèse de différents produits polycycliques. Une séquence one-pot, multicomposants, Diels-Alder/allylboration a été optimisée donnant différentes structures suivant le dienophile et l'aldehyde employé. Dans le but de diversifier la chimie du produit résultant de la réaction nitroso-ène, une autre séquence a été mise au point utilisant la synthèse des pyrroles. Une voie multi-étape a permis la synthèse de nouvelles structures bicycliques incorporant une oxazine et un pyrrole
This thesis presents the reactivity of dienylboronated compounds towards arylnitroso and carbonylnitroso derivatives and its use in the synthesis of heterocyclic and polycyclics compounds. The first study focused on the reactivity of dienylboronate compounds with arylnitroso derivatives resulting in pyrrole or furan products. The outcome and efficiency of the reaction is related to the boron on the dienyl moiety and the solvent used. Using the certain conditions, pyrroles, boronated MIDA ester oxazines or nitrones could be obtained. A one-pot strategy was then applied to synthesise oxazoline derivatives using nitrones as an intermediate. Theoretical, as well as experimental, work has supported that the formation of the pyrrole was obtained by a regioselective nitroso Diels-Alder reaction/rearrangement/borate elimination cascade process. Details on the nitrone formation have not been clarified, but further investigations are on-going. Secondly, attention was focused on the reactivity of dienylboronate compounds with carbonylnitroso derivatives. Contrary to the arylnitroso species, the nature of the carbonylnitroso had a dramatic impact on reactivity. On the one hand, similar reactivity towards the formation of pyrroles and boronated MIDA ester oxazines was observed, however, by employing a higher electron-deficient carbonylnitroso species, the product resulting from a nitroso-ene reaction was obtained. Ene-product was used as the key intermediate for the synthesis of different polycyclic compounds. A multicomponent, one-pot, Diels-Alder/allylboration procedure was optimised to yield various structures depending on the nature of the dienophile and the aldehyde. To diversify the chemistry of the ene-product another sequence was designed using the pyrrole synthesis. A multi-step pathway was optimised to afford novel fused bicylic oxazine-pyrrole products

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40

Dilek, Özlem. "Synthesis and spectroscopic characterization of fluorescent boron dipyrromethene (BDP) probes for site specific bioorthogonal labeling of proteins." Diss., Online access via UMI:, 2009.

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41

Gerdin, Martin. "Silaborations of Unsaturated Compounds." Doctoral thesis, Stockholm : Chemical Science and Engineering, Kungliga Tekniska högskolan (KTH), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9440.

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42

El-Assiery, Saied Abdullah. "Synthesis of compounds containing phenolic or boronic acid residues by reaction of boron hydrides with metallated systems." Thesis, Lancaster University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317402.

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43

Sivrikaya, Osman. "Use Of Boron Based Binders In Pelletization Of Iron Ores." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613323/index.pdf.

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Bentonite is the most preferred silicate-based binder in iron ore pelletizing. However, it is considered as an impurity due to its high SiO2 and Al2O3 content. The iron-making economy is adversely affected by the addition of bentonite or other silicate-based binders. In recent years, impurity-free alternative binders have been tested in order to replace bentonite or to lower the bentonite dosage. Organic binders yield good quality green and dry pellets. However, they fail to impart enough mechanical strength to the preheated and fired pellets as a result of insufficient slag bonding. Thus, they have not found widespread application in the industry. The addition of boron compounds into pellet mix is proposed as a potential solution to overcome the insufficient compressive strengths of preheated and fired pellets produced with organic binders. During the experiments, some organic binders and boron compounds were tested as alternative binders to bentonite either alone or in combination, for both magnetite and hematite pellets. The performances of the tested binders on pellet qualities: balling, wet pellet moisture content, drop number, pellet compressive strengths (wet - dry - preheated - fired), dustiness, porosity, mineralogy, morphology, chemical contents, reducibility and swelling index have been compared with the performances of reference bentonite binder. The results of the tests showed that, the quality of pellets are insufficient when organic binders or calcined colemanite used as binder alone. The former failed to provide sufficient preheated and fired pellet strengths, the latter failed in terms of wet and dry pellet quality. However, good quality wet, dry, preheated and fired pellets could be produced with combination of these two binders. Calcined colemanite addition into pellets made with organic binders was tested in different dosages (0.25-1.00%). Results showed that with increasing dosage of calcined colemanite both strengths of preheated and fired pellets increased linearly. It was found that as low as 0.50% calcined colemanite addition equally-performed on magnetite fired magnetite pellets at 1300oC when compared with the performance of the reference bentonite binder. However, its performance was better on hematite pellets in order to improve the pellet compressive strengths. In addition, stronger pellets could be produced at lower firing temperatures like 1100oC with the addition of calcined colemanite. The reason of the improved preheated and fired compressive strengths of pellets bonded with calcined colemanite was due to the physical melting of calcined colemanite at the contact point of iron oxide grains during thermal treatment. It was found that bentonite bonded pellets fired at 1300oC were more reducible than those of produced with calcined colemanite addition. Swelling indices of these pellets were determined in the industrially acceptable limits. The chemical and mineralogical analyses results showed that the combined binders did not contaminate the pellet composition since the organic binders burnt-out without residue and colemanite does not contain much impurity.

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44

Middlemas, Michael Robert. "Fabrication, strength and oxidation of molybdenum-silicon-boron alloys from reaction synthesis." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28253.

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Thesis (M. S.)--Materials Science and Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Cochran, Joe; Committee Member: Berczik, Doug; Committee Member: Sanders, Tom; Committee Member: Sandhage, Ken; Committee Member: Thadhani, Naresh.

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45

COELHO, MARCELO L. R. "Estudo da influência do teor de TiBsub(2), obtido pela reação in situ de Bsub(4)C e TiC, nas propriedades mecânicas de cerâmicas a base de Bsub(4)C." reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10110.

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Made available in DSpace on 2014-10-09T12:34:52Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T14:08:21Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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46

Thadani, Avinash N. "Boron tethered intramolecular Diels-Alder cycloadditions and addition of allyl- and crotyltrifluoroborates to carbonyl compounds in biphasic media." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ63605.pdf.

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47

Stone, Cora Emma. "Neutron studies of amorphous solids." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396244.

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48

Dogan, Mehmet. "Production And Characterization Of Boron Containing Flame Retardant Polyamide-6 And Polypropylene Composites And Fibers." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613266/index.pdf.

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The main objective of this study was to produce flame retardant polyamide-6 (PA-6) and polypropylene (PP) composites and fibers containing boron compounds. The synergistic effect on flame retardancy of boron compounds (boron silicon containing oligomer (BSi), zinc borate (ZnB), boron phosphate (BPO4), metal oxide doped BPO4 and lanthanum borate (LaB)) with conventional flame retardants were investigated. The synergistic effect of nano-clay with commercial flame retardants was also investigated in order to reduce the total amount of flame retardant that is essential for fiber applications. The UL-94, limiting oxygen index (LOI), differential scanning calorimeter (DSC), thermal gravimetric analysis (TGA), fourrier transform infrared spectroscopy (FTIR) and cone calorimeter tests were conducted on composite materials in order to investigate the effect of synergy agents on the flame retardant and thermal properties of conventional flame retardant containing PA-6 and PP composites. According to the results from composite materials, boron compounds and clay showed synergistic effect with phosphorus based commercial flame retardants by acting generally with a condensed phase mechanism by increasing the char formation and/or by increasing the barrier effect of the final char residue. Inspired from the previous studies, firstly, only nano-sized BPO4 containing flame retardant fibers were produced and characterized. In the view of the results obtained from the composite trials, the boron compounds and organo clay were used with phosphorus based flame retardants to produce flame retardant fibers. The characterization of fiber samples were made with mechanical testing, melt flow index measurements (MFI), TGA, DSC, SEM and Micro Combustion Calorimeter (MCC) tests. According to the results from fiber samples, the inclusion of BPO4 reduced the peak heat release rate of the pure PA-6 and PP fiber. The reduction for PA-6 is higher than the PP fiber due to char forming character of PA-6. The usage of boron compounds and clay with phosphorus based flame retardants caused further reduction of peak heat release rate (PHRR) and total heat release values and increased the char formation. The amount of reduction of PHRR and total heat release (THR) is not so much due to the thermally thin character of fiber samples of nearly 40 microns. It is evident that a fabric made with these fibers will show better flame retardant behavior than single fiber tests due to its thick character with respect to the fiber samples.

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Ahmadian-Najafabadi, Mehdi. "Sintering, microstructure and properties of WC-FeAl-B and WC-Ni3Al-B composite materials." Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20061121.154813/index.html.

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50

Davis, Matthew Christopher 1970. "Chemical syntheses of rationally-designed pyridine and pyrazine derivatives and boron-containing compounds for inhibition of Mycobacterium tuberculosis in vitro." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282393.

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Since tuberculosis incidence has been increasing world-wide due, in part, to infection from drug-resistant strains of Mycobacterium tuberculosis, there is a need for new, more effective drugs for treatment (Bloom and Murray 1992). To this end, the strategies of medicinal chemistry were applied this problem and a group of 22 small organic molecules were prepared as inhibitors of mycobacterial growth. The group is comprised of pyridines and pyrazines, boronic acids and esters, and diazaborines. The 10 pyridine and pyrazine compounds are composed of 5 pyridine derivatives (3PYSO, 4PYSO, 3PYS, 4PYS, 3PYA) including 3 unreported (3PYS, 4PYS, 3PYA), and 5 pyrazine derivatives (PZSO, PZS, POAH, PZUREA, PZCS) including 2 unreported (PZUREA, PZCS). These 10 compounds have a rationale for antimycobacterial activity that involves mycobacterial penetration, then bioactivation by enzyme systems known to exists in mycobacteria to metabolites expected to be toxic to the organism. The 6 boronic acids and esters are composed of 3 boronic acids (3PYB, 4PYB, NPBA) and 3 boronic acid esters (NPOB, DEPYB, BDPYB), with BDPYB unreported. The compounds were expected to have antimycobacterial activity due to the ability of boron to form charged, reversible tetrahedral complexes and compete for enzyme active-sites. Since diazaborines were shown to inhibit bacterial growth by a novel mechanism, 6 benzodiazaborines were also synthesized, composed of 2 [2,3,1] -benzo-e-diazaborines (SDZB, PDZB) and 4 new [2,4,1] -benzo-e-diazaborines (OBDZB, OPDZB, TPDZB, PZDZB; Baldock, Rafferty et al. 1996). In order to prepare aza-analogs of ASDZB and APDZB, a lesser-known synthetic strategy relying on a dilithiated intermediate was used in an attempt of their preparation as well its successful application for SDZB and PDZB (Sharp and Skinner 1986). All of the compounds were then evaluated in vitro for growth inhibition of wild-type M. tuberculosis H₃₇Rᵥ by Dr. Scott G. Franzblau at LSU. Of the compounds tested, the diazaborines were the most active, although much less than one of the best available drugs, isoniazid. The majority of the group had activities comparable to or better than another widely used drug, pyrazinamide.

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Dissertations / Theses on the topic 'Boron compounds'

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