CARBON

Author: GABRIEL BUGUÑA GEMMA.
Year: 2004.
University: AUTÓNOMA DE BARCELONA.
Place of defense: INSTITUT DE CIÈNCIA DE MATERIALS DE BARCELONA.
Place of preparation: ESCUELA DE POSTGRADO.

Summary: The carbon nanotubes (SWNT) are produced by electric arc in a material highly impure metal content and deviant forms of carbon. This material has been purified with different successive treatments. First treatments with nitric acid, which have succeeded in reducing the metal content up to 3.4% by weight. We subsequent thermal oxidation treatment, which helped eliminate the messy carbon ratios areas getting in the way of tangential connection carbon nanotubes of 21.4. Attempts were also made to make recocidos unsuccessfully. To solubilizar these materials were tested with different routes of funcionalización aromatic amines and alifácticas, with some of them perfluoradas. Depending dela basicity of these mines, XPS analysis revealed that: SWNTs funcionalizados with octadecilamina had this amine covalentemente linked via a link amides. The SWNTs funcionarizados with amines perfluoradas have amines adsorbed on its surface because of its low basicity. And manotubos funcionarizados with 2-Aminoanthracene are part of the maina quimiadsorbida and part fisiadsorbida. The funcionalización of nanotubes has emerged as a good method for solubilizar or disperse these materials in different solvents.

Author: LECUMBERRI MUNÁRRIZ AINARA.
Year: 2004.
University: NAVARRA.
Place of defense: DEPARTAMENTO DE QUÍMICA APLICADA.
Place of preparation: DEPARTAMENTO DE QUÍMICA APLICADA.

Summary: In this PhD thesis describes the use of alfa-hidroxicetonas derived from camphor in alkylation reactions and Diels-Alder asymmetrical. Thus, it is carried out for the first time in an asymmetrical manner conversion of acetylene compounds carbonilicos alfa-sustituidos with high purity enentiomérica.La alfa-hidroximitilcetona derived from the camphor is easily prepared using sequential acetileno.La introduction of two groups rent and subsequent cleavage of oxidant compounds obtained leads to carboxylic acids enantioméricamente pure recovering at the same time the source of information chiral R (+) -alcanfor.Igualmente treatment of produrctos of alkylation derived from camphor cn borano or reagents organolíticos and subsequent excision oxidizer of the products resulted in aldehydes and ketones respectively with excesses ensntioméricos excess of 96%. The usefulness of these substrates derived from camphor in the alkylation reaction due demonstrated in the synthesis of acid R-2 propiloctanoico, therapeutic agent for Alzheimer's disease and its enantiomer. On the other hand, they were prepared alfa-hidroxienonas derived from camphor for use in reactions Diels-Alder asymmetrical using as organocatalizadores acids Brosted such as acid trifluoroacético and acid trifluorometanosulfónico that activated the filodieno through the formation of bridges hidrógeno.Las reactions Diels-Alder using both cyclic and acyclic dienos It should be noted that alfa-hidroxienonas beta-sustituidas ocn groups rent or arilo also were effective in the reaction of Diels-Alder.Los adducts obtained were transformed into carboxylic acids and ketones optically pure recovering source information chirality.

Author: BERENGUER MURCIA ÁNGEL.
Year: 2004.
University: ALICANTE.
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: UNIVERSIDAD DE ALICANTE.

Summary: This Doctoral thesis discusses the preparation and study of the type zeolite membranes IFM (silicalita-1) on carbonaceous materials, as well as the study on the possibility of developing new reactors membrane combining the techniques of deposit and the deposit by electrophoretic jump potential . Some of the materials developed in this study have been characterized using a system based on a permeation cell Wicke-Kallenbach. This thesis also contains a detailed and comprehensive study on the preparation and characterization of materials Nanostructured MCM-41 to deepen their understanding. Finally, Bimetal nanoparticles have been prepared using the method by reducing solvent to obtain colloid particles Bimetal sized nano (2 mm) with a distribution of particle sizes very close. These nanoparticles have proven to be highly active and selective in different reactions of a strong interest in industrial chemistry and environmental.

Author: RIBAS ARIÑO JORDI.
Year: 2005.
University: BARCELONA.
Place of defense: FACULTAD DE QUÍMICA - UNIVERSIDAD DE BARCELONA.
Place of preparation: DEPARTAMENTO DE QUÍMICA FÍSICA, FACULTAD DE QUÍMICA, UNIVERSIDAD DE BARCELONA.

Summary: The research projects carried out during this Doctoral Thesis deal with the theoretical level study / computational mechanisms of magnetic interaction in various organic and inorganic systems. Listed below are the most significant conclusions of this thesis, classified according to the systems that have been studied. MECHANISMS OF INTERACTION MAGNET IN POLYMERS FOR FULERENO C60 A - The most plausible mechanism able to justify the presence of magnetic moments in the ferromagnetic phase Polymer C60 is the generation that associates of those moments with the breakdown of one of the two links united CC maintaining the fulerenos one another. B-LA rupture of one of these links CC involves generating a hat trick (T2), so that each of the two fulerenos united by the DC link becomes a kind radicalaria. C-Breaking links CC takes place after subjecting the polymer C60 at high pressures and temperatures. D - Different triplets T2 that are generated in the sound after treatment of high pressures and temperatures are magnetically coupled to one another, since it has been shown that fulerenos C60 can serve as excellent couplers ferromagnetic. Accordingly, the mechanisms based on the severance of links CC is also capable of showing that the polymer C60 behaves like a magnet in molecular basis. E-It has been shown that mechanisms based on the generation of vacancies and vacancy in the generation and the generation of structures open molecules C60 to justify the presence of magnetic moments in the ferromagnetic phase Polymer C60, are not valid because contradict several experimental facts. STRUCTURE ELECTRONICS AND INTERACTION MAGNET IN METALOPORFIRINAS A-analysis of the correlations magneto-estructurales the family of basic molecular magnets [MnTPP] [TCNE] shows that the constant magnetic coupling between [TCNE] - and [Mn () ] + is antiferromagnética for all guidelines concerning possible between a molecule and the other. B - As the angle between the planes of [Mn ()] + and [TCNE] - falls, the magnetic coupling constant becomes more antiferromagnética. The maximum value of the constant is associated with an angle between planes 30 º. C-J variation depending on the relative orientation between [TCNE] - and [Mn ()] + is very complex because there is more than one route of magnetic interaction between the two species, in particular, has been check that the SOMO [TCNE] - may interact with the orbital dyz, dza and dz2 of molécular [Mn ()] +. D-Kahn model is not able to reproduce completely trends in the values of J calculated with the functional B3LYP, which shows that the methods based on first principles are the ones who should preferably be used to predict trends values J. E-mail key state of the complex oxiheno is a singulete multireferente (1A ') in which the configuration Pauli (Fe2 + -Os) and the configuration of Weiss (Fe3 +-Os) have similar weight. F-excited states of the complex oxihemo are extremely close to the ground state energy. Specifically, in a range of 7.5 kcal / mol were found four states excited, some of them charge transfer. The presence of these excited states justifies the magnetic data and espectroscopios system oxihemo (with the temperature dependence of magnetic susceptibility and cleavage cuadropolar in the spectra Mà ¶ ssbauer) and it is essential to understand the mechanism of reversible binding of oxygen to the group hemo . G-An analysis of the potential curves of various electronic states of the complex oxihemo reveals that the key factors that determine the process unión-disociación oxygen to be fully reversible hemo group are: the existence of a ímino van der Waals prior to the formation of a link between iron and oxygen; the dissociative at short distances from the states in which dissociates the comp 8 Nearby oxy 81st hemo (statements coming from the coupling between 5Fe2 + and 3O2) and the slight stabilization of the least state 1A 'off the energy of dissociation products. INTERACTION MAGNET IN COMPOUND POLINUCLEARES OF cUII A-system [Cu4 (aspartate) 2 (bby) 4 (H2O) 3] provides an example of the inability of asinar what avenues of magnetic interactions are ferromagnéticas and what antiferromagnéticas based only on magnetic susceptibility data. It has been shown that the theoretical calculations are a useful tool to establish without ambigà ¼ ages topology magnetic systems in such cases. B-bridge ligands derived from m-fenileno can become excellent couplers ferromagnetic systems Type CuII-ligando puente-CuII. C - There is a correlation between the negative charge accumulated in the ring bencénico of m-fenileno and constant magnetic coupling between CuII: a greater burden negavia in the ring bencénico, the greater the ferromagnetic coupling constant between CuII. D-That correlation, established by DFT calculations, has led to synthesize a new compound dinuclear of CuII with ferromagnetic interaction, and predict how it must design new ligands for increasing the magnetic coupling constant with a value of 325 cm-1.

Author: ORTIZ JIMENEZ GREGORIO FRANCISCO MARIO.
Year: 2005.
University: CÓRDOBA.
Place of defense: CAMPUS DE RABANALES.
Place of preparation: CAMPUS DE RABANALES.

Summary: The overall objective of this work is to obtain and study of new materials anódicos for use in lithium batteries and sodium. To this end have been selected samples of various nature carbonoso, ranging from materials grafiticos up materials with greater disorder, this is the case of coke turbostráticos and hard carbons not grafitizables. It has also studied different morphologies, such as nanofibres and particulate microesféricas. They also explored various metal oxides, including iron oxides, cobalt and tin. The work has been conducted in the following fields: 1 - Preparation and modification of carbonaceous materials. 2, physico-Characterization, textural, structural and electrochemical properties. 3, - The study of the mechanisms of reactions and evaluating the changes arising in the electrode after the intercalation of alkali metal. It demonstrated the usefulness of metallic oxides disperse phase in a matrix of carbon. Thermal treatments and / or hydrothermal of carbon nanofibres to improve the retention capacity for batteries ión-sodio were obtained reversible capacities on the order of 300 mAhg-1 using carbon microspheres obtained from resorcionol and formaldehyde. In the case of Li-ion batteries battery, the capacity reversible hit was of the order of 400 mAhg-1.

Author: ALMAZÁN ALMAZÁN MARÍA DEL CARMEN.
Year: 2005.
University: GRANADA.
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: Much of the waste consists of plastic materials, of which the most commonly used is the politereflato ethylene PET. At present only a small proportion goes to a second use, the rest is eliminated either through indiscriminate burning is either abandoned landfills. Obtaining activated carbons with good textural characteristics from these waste materials presents a dual interest. On the one hand, be derived materials with high added value from materials whose cost is zero and secondly, would be a very interesting way of recycling. In this Doctoral Thesis has been prepared and characterized many activated carbons from PET, directly and after being subjected to various treatments prior to carbonization and activation process. Moreover, its implementation has been studied as absorbents air pollutants for which removal is a priority, such as benzene, trichlorethylene and 1,2-dichloroethane.

Author: ARCEO REBOLLO ELENA.
Year: 2005.
University: PÚBLICA DE NAVARRA.
Place of defense: DEPARTAMENTO DE QUÍMICA APLICADA.
Place of preparation: DEPARTAMENTO DE QUÍMICA APLICADA.

Summary: In this Doctoral Thesis has been studied using alpha '-hidroxienonas as new substrates in reactions cicloadición asymmetrical, specifically in reaction Diels-Alder and the reaction 1,3-dipolar with nitronas. In reaction 1,3-dipolar with nitronas have been used alfa'-hidroxienonas chiral derived from (R) -alcanfor in combination with catalytic amounts of Cu (TfO) 2, or alfa'-hidroxienonas aquirales a catalyst chiral bisoxazolina- Cu (II). In both processes, the reaction conditions have been optimized so as to obtain the relevant isoxazolidinas with good yields and high regio reaching and estereoselectividades. These findings are relevant because it is the first time that this type of substrates used in the reaction 1,3-dipolar and levels of selectivity achieved represent the best results to date systems alquenoil not replaced in beta position. There have also been employed for the first time alfa'-hidroxienonas aquirales as dienófilos in reaction Diels-Alder. Using alfa'-hidroxienonas not replaced beta position as a catalyst and a complex bisoxazolina-Cu (II) have achieved excellent values enantioselectividad even in the reaction with little dienos reagents. With alfa'-hidroxienonas less reactive, replaced by beta position groups rent or arilo, the reaction with ciclopentadieno leads to high levels of selectivity endo / exo and enantioselectividad. These results have demonstrated the effectiveness of coordination 1.4 of alfa'- hidroxienonas and thus its effectiveness as substrates chelating bidentados may well be regarded as new templates reactions cicloadición asymmetrical. Moreover, from cicloaductos obtained accessed easily to acids, ketones, aldehydes with high optical purity, recovering the source chiral (version diastereoselectiva), or getting acetone as the only byproduct of the reaction (version enantioselectiva ).

Author: ALVAREZ GARCIA SONIA.
Year: 2006.
University: OVIEDO.
Place of defense: E.T.S. DE INGENIEROS DE MINAS DE OVIEDO.
Place of preparation: ESCUELA TECNICA SUPERIOR DE INGENIEROS DE MINAS DE OVIEDO.

Summary: IN THIS WORK IS RAISED THE PREPARATION OF MATERIALS AND CHARACTERIZATION OF CARBON MESOPOROSOS WITH SPECIAL ATTENTION TO ITS USE AS ELECTRODES IN CONDENSADORES ELECTROQUÍMICOS. IN THE FIRST PART OF WORK IS THIS STUDY L APREPARACION OF VARIOUS MATERIALS CARBON MESOPOROSO FROM THE TECHNICAL NANOMOLDEO. WILL THEREFORE BE USED MATERIALS SILICE MESOESTRUCTURADA AS NANOMOLDE. FEATURES OF THE MATERIALS OF STRUCTURAL SILICE HAVE BEEN CONTROLLED FROM USE OF VARIOUS SURFACTANTES AND THE MODIFICATION OF APRAMETROS FOR SYNTHESIS (CONCENTRATION REAGENTS AND CATALIZADORES, DEGREE OF AGITACION, pH, RESPONSE TIMES AND TEMPERATURES). THIS WAY HAVE BEEN ACHIEVED SINTETIZAR MATERIALS WITH CARBON DIFFERENT MORFOLOGIAS (AGLOMERADOS SUBMICROMETRICOS, FIELDS MICROMETRICAS And MONOLITOS OF 2-3 CM OF DIAMETRO) SIZE OF PORO (2-10 nm) AND VARIOUS TYPES OF POROSIDAD (UNIMODAL, BIMODAL And TEXTURAL ). IN THE SECOND PART OF THIS IS LLEVO WORKING OUT A STUDY ON THE INFLUENCE THAT FEATURES TEXTURALES AND CHEMICAL MATERIALS THAT THE CARBON MESOPOROSO SINTETIZADOS HAVE ON ITS USE AS ELECTRODES IN CONDENSADORES ELECTROQUIMICOS. FOR COMPARATIVE SE ANALIZARON ALSO VARIOUS CARBONES ASSETS BUSINESS. SUCH STUDY INCLUYO THE REALIZATION OF CYCLES GALVANOSTATICOS LOADING AND UNLOADING AND CYCLES VOLTAMPEROMETRICOS, LLEVO AND OUT IN THE PRESENCE OF VARIOUS ELECTROLITOS. SE DEMOSTRO THE INFLUENCE THAT SUEPRFICIE SPECIFIED AND THE CONCENTRATION OF OXYGEN GROUPS SURFACE OF THE MATERIALS IN CARBON HAVE THEIR PROPERTIES CAPACITIVAS. SE OBSERVO ALSO THAT ONE SIZE OF PORO AROUND 2 nm COMES SUFICIENTEMENTE BIG AS A GOOD TO ALLOW ACCESS OF ION OF ELECTROLITOS ANY SURFACE CARBONOSA.