Mostrar el registro sencillo del ítem

dc.contributorUniversitat Jaume I. Departament de Química Física i Analítica
dc.contributor.authorBeltrán Álvarez, Tomás Francisco
dc.date.accessioned2014-09-23T09:41:18Z
dc.date.accessioned2024-03-25T13:00:50Z
dc.date.available2014-09-23T09:41:18Z
dc.date.available2024-03-25T13:00:50Z
dc.date.issued2013-09-27
dc.identifier.isbn978-84-697-1305-1
dc.identifier.urihttp://hdl.handle.net/10803/277562
dc.description.abstract<p> The research work described in this thesis presents the synthesis, characterization and properties of a new family of trimetallic M<sub>3</sub>(&mu;<sub>3</sub>-S)(&mu;<sub>2</sub>-S)<sub>3 </sub>molybdenum and tungsten sulfide clusters. Functionalization of the cluster unit has been done by incorporating different chelating ligands such as diphosphines and heterodentate aminophosphines in order to confer specific physicochemical properties such as water solubility or catalytic activity. In particular, water&nbsp;soluble&nbsp;diphosphines&nbsp;and&nbsp;aminophosphines&nbsp;have&nbsp;been&nbsp;coordinated&nbsp;to&nbsp;the&nbsp;M<sub>3</sub>S<sub>4</sub> unit in order to evaluate the potential applications of these new derivatives in environmentally friendly biphasic catalysis and homogenous organic catalysis, respectively.</p> <p> The first chapter of the thesis describes the background, relevance and importance of the chemistry of transition metal clusters. General aspects on the chemistry of molybdenum and tungsten trinuclear clusters are shown together with their last novel applications. The second chapter shows the main objectives of this research project.</p> <p> The preparation and characterization of novel water soluble cluster compounds of formula [M<sub>3</sub>S<sub>4</sub>X<sub>3</sub>(hydroxyalkyldiphosphine)<sub>3</sub>]<sup>+</sup> (M=Mo, W; X=Cl, Br; hydroxyalkyldiphosphine = dhprpe, dhbupe) is described in chapter 3. Detailed studies based on <sup>31</sup>P{<sup>1</sup>H} NMR and electrospray ionization mass spectrometry techniques have been carried out in order to understand the complex pH dependent aqueous speciation of these water soluble clusters.</p> <p> In chapter 4, the synthesis of molybdenum (IV) hydroxo [Mo<sub>3</sub>S<sub>4</sub>(dmpe)<sub>3</sub>(OH)<sub>3</sub>]<sup>+</sup>&nbsp; and hydrosulfido [Mo<sub>3</sub>S<sub>4</sub>(dmpe)<sub>3</sub>(SH)<sub>3</sub>]<sup>+</sup> trimetallic cuboidal cluster complexes is presented. A comparative study between molybdenum and tungsten of the gas-phase aldehyde production from the M<sub>3</sub>S<sub>4</sub> ethoxo complexes combining collision induced dissociation experiments with computational DFT calculations is also discussed.</p> <p> In chapter 5, the catalytic activity of molybdenum and tungsten (IV) cluster hydrides of formula [M<sub>3</sub>S<sub>4</sub>H<sub>3</sub>(dmpe)<sub>3</sub>]<sup>+</sup> (M=Mo, W) in the regioselective hydrodefluorination of pentafluoropyridine at the 4-position has been evaluated. A mechanism for the catalytic reaction has been proposed based on experimental results and DFT calculations. Additionally, the fluorinated [M<sub>3</sub>S<sub>4</sub>F<sub>3</sub>(dmpe)<sub>3</sub>]<sup>+</sup> complexes have been fully characterized.</p> <p> In chapter 6, an aminophosphine ligand, (2-aminoethyl)diphenylphosphine (edpp),&nbsp; containing a NH<sub>2</sub> protonic function has been coordinated to the molybdenum and tungsten M<sub>3</sub>(&mu;<sub>3</sub>-S)(&mu;-S)<sub>3</sub> cluster unit to afford for the first time trimetallic aminophosphine complexes. The activity of the molybdenum [Mo<sub>3</sub>S<sub>4</sub>X<sub>3</sub>(edpp)<sub>3</sub>]<sup>+</sup> (X=Cl, Br) clusters in the catalytic transfer hydrogenation of nitroarenes has been investigated. Cluster catalysis is demonstrated from reaction monitoring using a pressurized sample infusion (PSI) ESI mass spectrometric technique. The reactivity of the tungsten [W<sub>3</sub>S<sub>4</sub>Br<sub>3</sub>(edpp)<sub>3</sub>]<sup>+</sup> cation&nbsp; towards alcohols, bases and halides salts has been investigated using a combination of spectrometric and spectroscopic techniques.&nbsp; Molybdenum and tungsten [M<sub>3</sub>S<sub>4</sub>X<sub>3</sub>(edpp)<sub>3</sub>]<sup>+</sup> (X=Cl, Br) complexes have been derivatized to afford a novel family of&nbsp; trinuclear clusters bearing alkoxo terminal ligands.</p> <p> In Chapter 7, details of the synthetic procedures together with the experimental and theoretical characterization are shown. Finally, chapter 8 shows the main conclusions of this Ph. D. thesis.</p>eng
dc.format.extent393 p.
dc.format.mimetypeapplication/pdf
dc.language.isospa
dc.publisherUniversitat Jaume I
dc.sourceTDX (Tesis Doctorals en Xarxa)
dc.subjectClúster
dc.subjectMolibdeno
dc.subjectWolframio
dc.subjectDifosfina
dc.subjectAminofosfina
dc.subjectCatálisis
dc.subjectCálculos DFT
dc.subjectMecanismos de reacción
dc.subject.otherQuímica Fí­sica
dc.titleClústeres Sulfuro Trimetálicos de Molibdeno y Wolframio Funcionalizados con Ligandos Difosfina o Aminofosfina y sus Aplicaciones en Catálisis Orgánica
dc.typeinfo:eu-repo/semantics/doctoralThesis
dc.typeinfo:eu-repo/semantics/publishedVersion
dc.subject.udc5cat
dc.subject.udc54cat
dc.subject.udc544cat
dc.subject.udc546cat
dc.contributor.directorLlusar Barelles, Rosa María
dc.rights.licenseADVERTIMENT. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs.
dc.rights.accessLevelinfo:eu-repo/semantics/openAccess
dc.contributor.authorsendemailtrue
dc.embargo.termscap


Ficheros en el ítem

FicherosTamañoFormatoVer

No hay ficheros asociados a este ítem.

Este ítem aparece en la(s) siguiente(s) colección(ones)

Mostrar el registro sencillo del ítem