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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.
11

The synthesis of perfluorinated compounds by direct fluorination: organometallic compounds and carboranes

Callahan, Ryan Patrick 17 March 2011 (has links)
Not available / text
12

Studies into synthetic methods and structural changes in metallacarboranes

McAvoy, Catherine January 2001 (has links)
No description available.
13

Electronic structure and evolution of dehydrogenation of orthocarborane, metacarborane, paracarborane, ortho-phosphacarborane and meta-phosphacarborane

Balaz, Snjezana. January 1900 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2007. / Title from title screen (site viewed July 9, 2007). PDF text: vii, 102 p. : ill. (some col.) UMI publication number: AAT 3245348. Includes bibliographical references. Also available in microfilm and microfiche formats.
14

Synthesis, structural characterization and reactivity of 13- and 14-vertex carboranes. / CUHK electronic theses & dissertations collection

January 2011 (has links)
Zhang, Jian. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 263-289). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
15

Synthesis, structural characterization and reactivity of twelve-, thirteen-, and fourteen-vertex carboranes. / CUHK electronic theses & dissertations collection

January 2013 (has links)
Zheng, Fangrui. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 181-197). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
16

Synthesis, structure and reactivity studies on metal carborane complexes of groups 1, 4 and lanthanides. / CUHK electronic theses & dissertations collection

January 2002 (has links)
Guofu Zi. / "June 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 164-173). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
17

Synthesis, structural characterization and reactivity of metallacarboranes of lanthanides and early transition metals. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Alkane elimination reaction of Hf(CH2SiMe3) 4 with a zwitterionic salt 1-Me2NHCH2CH2 -1,3-C2B10H12 has resulted in the isolation and structurally characterization of the first example of half-sandwich group 4 metallacarborane alkyls of the C2B10 system. This is also a new route to high-valent group 4 metallacarboranes. / Alkane or amine elimination reactions are also effective methods for the preparation of half-sandwich group 4 metal] acarboranes of the C 2B9 system. The Lewis base functionalized sidearm can effectively stabilize half-sandwich group 4 metallacarborane alkyls through intramolecular coordination. These novel metallacarborane alkyls undergo insertion reaction with alkyne and intramolecular hydrogen atom abstraction reactions. / High-valent group 4 half-sandwich metallacarboranes incorporating an eta 7-carboranyl ligand have been prepared and structurally characterized. The heteroatom-containing pendant sidearms on the carborane cage are both electronically and entropically necessary for the formation of such complexes. / Reaction of [(Me2NCH2CH2)C2B 10H11]Na2 with YCl3 gives eta 1:eta6-[(Me2NCH2CH2)C 2B10H11]YCl(THF)3 containing an exopolyhedral Y-Cl bond, which offers an important intermediate for the preparation of lanthanacarboranes bearing the Ln-C or Ln-X (X = heteroatoms) bonds. On the other hand, it implies that Lewis base functionalized carboranes can stabilize half-sandwich metallacarboranes via the coordination of heteroatom from the sidearm. Silylamine elimination reactions of the neutral ligand 7-Me2NHCH2CH2-7,8-C 2B9H11 with Ln[N(SiHMe2)2] 3(THF)2 are effective method for the preparation of half-sandwich lanthanacarboranes. / Reactions of alkali metal salt of these carboranes with LnCl3 in the presence of excess alkali metal afford a novel class of 13-vertex closo-metallacarboranes incorporating eta7-carboranyl ligands [{eta1:eta1:eta7-[(DCH 2CH2)RC2B10H10]Ln}{Na(solvent) x}]n. Structural studies show that the Lewis base functionalized sidearms have some effects on the coordination environments of the central metal atom, but do not change the gross structures of the 13-vertex closo-metallacarboranes. The reactivity patterns of these 13-vertex closo-metallacarboranes have been studied for the first time. / Several mono- and bisfunctional carboranes (DCH2CH2)RC 2B10H10 (R = H, DCH2CH2, D = MeO, Me2N) have been designed and successfully synthesized. They can be conveniently converted into the monoanions, the dianions and the tetraanions by treatment with suitable reagents. Their applications in organolanthanide and group 4 organometallic chemistry have been studied. / Cheung Mak-shuen. / "June 2005." / Adviser: Kevin W. P. Leung. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0258. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 169-181). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
18

Carborane derivatives with electron rich moieties. Synthesis, properties and electronic communication

Popescu, Radu‐Adrian 18 January 2013 (has links)
El treball que es presenta en aquesta tesi és la continuació i ampliació de la feina feta en el nostre grup de recerca en els darrers anys sobre derivats de l’o-carborà que porten grups rics en electrons. L’objectiu global de la tesi és la síntesis i l’estudi teòric d’aquests derivats. Gairebé tots els compostos sintetitzats en aquest treball s’han obtingut directament a partir de l’o-carborà. La funcionalització dels àtoms de carboni de l’o-carborà es fa en dos etapes. En un primer pas, s’afegeix un agent per arrancar el protons, com són els compostos organolitiats, les amides alcalines, els hidrurs alcalins; i tot seguit, s’afegeix un electròfil (diòxid de carboni, calcogen, halogen, halurs, epòxids, aldehids). Tot i que la substitució dels dos àtoms de carboni del clúster d’o-carborà S’obté pràcticament sempre, la monosubstitució no és gens trivial, perquè sempre ve acompanyada de la disubstitució. Per això, el primer objectiu d’aquest treball ha sigut l’estudi experimental i teòric de la influencia dels dissolvents eterats (Et2O, THF or DME) en la formació dels compostos organolitiats, utilitzant com a plataforma el 1,2-C2B10H12. Tot i que les fosfines de l’o-carborà són uns dels derivats més estudiats, la investigació de les seves propietats electròniques no ho ha sigut tant. Les carboranilfosfines varen ésser sintetitzades per primer cop fa més de 50 anys, però cap estudi sistemàtic i exhaustiu sobre les reaccions d’oxidació s’havia fet fins ara. Per tant, un altre objectiu d’aquest treball ha sigut l’estudi de les reaccions d’oxidació de les carboranilfosfines amb peròxid d’hidrogen, sofre i seleni; i la seva avaluació com a lligands. Un cop sintetitzats aquests compostos, hem fet un estudi teòric que ha tingut els següents objectius: i) veure la influència dels grups fosfina i fosfina oxidada en els efects electrònics del clúster d’o-carborà; ii) veure els efectes electrònics en les closo-carboranilmonofosfines; iii) veure la labilitat del enllaç fòsfor-calcogen en els monocalcògens dels carboranilmono- i carboranildifosfines; iv) estudiar dels processos de oxidació i degradació; v) estudiar la comunicació intramolecular en les carboranildifosfines aniòniques oxidades. Un altre grup ric en electrons és el grup formil (-CHO), que una vegada afegit a un clúster d’o-carborà, veure les seves propietats altament modificades. Tot i que el carboranilformaldehid es coneix des de fa temps, hi ha pocs estudis sobre la seva reactivitat. Per tant un altre objectiu d’aquest treball ha sigut l’estudi de la reactivitat d’aquest compost amb la finalitat d’obtenir nous derivats. Per això hem estudiat: i) l’addició nucleofílica al grup carbonílic del derivat litiat de l’o-carborà per obtenir derivats amb múltiples clústers d’o-carborà; ii) la substitució electrofílica dels substrats aromàtics emprant el carboranilformaldehid activat amb la finalitat d’obtenir derivats de l’o-carborà amb propietats luminescents; iii) les reaccions de Wittig i Horner-Wadaworth-Emmons emprant ja sigui el carboranilformaldehid ó els derivats de l’o-carborà amb grups fosfonat i sals de fosfoni. Per l’últim hem estudiat la síntesis de nous derivats utilitzant com a plataforma la carboranilpiridina. Les reaccions estudiades han sigut: i) la metal·lació de la carboranilpiridina amb complexos de Pd(II), Ir(III), Rh(III) i Ru(II); ii) la síntesis de lligands híbrids carboranilpiridina-fosfina i les seves reaccions de complexació amb Pd(II) i Rh(I); iii) la síntesis de un derivat de la carboranilpiridina que inclou un grup borà; iv) la síntesis de un derivat cobaltabis(dicarballur)-dipiridina. / The work presented in this manuscript is the continuation and extension of the work done in our group during the last years on the carborane derivatives with electron rich moieties. The main objective of this work is to synthesize and to study by computational means new derivatives of carborane with electron rich moieties. Almost all the compounds synthesized in this work are directly achieved from o-carborane. The direct modification of the C vertexes of the o-carborane is done in two steps. First a deprotonating agent as organolithium compounds, alkali-metal amides or alkali-metal hydrides is added, followed by the addition of a suitable electrophile (carbon dioxide, chalcogens, halogens, halides, epoxides, aldehydes). Although the substitution at the both carbon atoms is always achieved, the monosubstitution is not so trivial, being almost always accompanied by the disubstituted derivative. For that, the first specific objective of this work was to study both experimentally and by computational means the influence of ethereal solvents (Et2O, THF or DME) on the formation of organolithiated compounds, based on the 1,2-C2B10H12 platform. Though the o-carborane derivatives with phosphorus moieties were the most studied synthetically and some of their properties were exploited, still work has to be done to understand their electronic properties that may ultimate lead to a rationalized design of new derivatives. The carboranylphosphines are known for more than 50 years ago, but no systematic and comprehensive investigation on their oxidation reactions were found in the literature as well as investigations on the electronic properties of these phosphines. For that the second specific objective was the study of the oxidation of carboranylphsophines with hydrogen peroxide, sulphur and selenium and to examine their properties as ligands. Once the synthetic study on the carboranylphosphines and their oxides and chalcogenides was completed, we proceeded with the third specific objective that was the computational study of the carboranylphosphines and their oxides and chalcogenides. The computational study contains: i) the contribution of phosphine and oxidized phosphine moieties to the electronic effects on the o-carborane cluster; ii) electronic effects in closo-carboranylmonophosphines; iii) the lability of the phosphorus-chalcogen bonds in carboranylmono- and carboranyldiphsophine monochalcogenides; iv) the oxidation/degradation processes study; and v) intramolecular communication in oxidized anionic carboranyldiphosphines. Other moiety that is rich in electrons is the formyl group, that once attached to o-carborane cluster its properties are highly modified. Though the carboranylformadehyde is long known in the literature, studies on its reactivity are rare. For that, the fourth objective was to understand the reactivity carboranylformaldehyde as platform for new derivatives. For that we studied: i) the nucleophilic addition to the carbonyl group with lithated carborane in order to synthesize “confined space” multi-cage compounds; ii) the electrophilic substitution reactions of aromatic substrates with activated carboranylformaldehyde, in order to obtain derivatives with luminescent properties; and iii) the Wittig and Horner-Wadaworth-Emmons reaction using carboranylformaldehyde and carborane containing phosphonates and phosphonium salts. The fifth specific objective was the study of carboranylpyridine as platform for new derivatives, for which we studied: i) the metalation reaction of carboranylpyridine with Pd(II), Ir(III), Rh(III) and Ru(II); ii) synthesis of carboranylpyridine-phosphine hybrid ligands and complexation reactions of these ligands through Pd(II) and Rh(I) complexes; iii) synthesis of carboranylpyridine-borane derivative; and iv) synthesis of cobalta(bisdicarbollide)-pyridine derivative.
19

Derivatives of dodecahalo-closo-dodecaborate di-anion

Avelar, Amy C. January 2009 (has links)
Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed April 2, 2010). Includes bibliographical references. Also issued in print.
20

The synthetic and bioinorganic chemistry of carboranes /

Schaffer, Paul. Valliant, John Fitzmaurice. January 1900 (has links)
Thesis (Ph.D.)--McMaster University, 2003. / Advisor: John Fitzmaurice Valliant. Accompanying CD-ROM contains the text, plus additional material (appendices I and II). Includes bibliographical references. Also available via World Wide Web.

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