MACROMOLECULAR CHEMISTRY

Author: GACEN ESBEC MARIA ISABEL.
Year: 2003.
University: POLITÉCNICA DE CATALUÑA.
Place of defense: Sala d'Actes de l'INTEXTER.
Place of preparation: ETSEIT, EDIFICI TR5 Campus TERRASSA.

Author: MOUNIR MOUNIA.
Year: 2004.
University: BARCELONA.
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: FACULTAT DE QUÍMICA DE LA UNIVERSIDAD DE BARCELONA.

Summary: The work of the thesis consisted in the design and synthesis of polygons via molecular self-assembly from its constituent units, which have been linear units (edges fluoride) type organometálico or organic, and angular units that have been complex plane square Pt and Pd (corners) based ligands difosnia and ligand ethylene diamine. The self-assembly reactions have resulted in a balance between triándulos and square and has been studied molecular composition of the same depending on different factors such as concentration, the solvent used or the angle of the bite phosphine ligand of the corners. The study of polygons molecular síntetizados, has been supplemented in some cases by conducting theoretical calculations, a quantitative study of molecular recognition or analyzing the interaction with DNA. There have also been synthesized compounds fluoroarílicos gold possessing behavior of liquid crystals.

Author: GARCIA DIAZ ALMUDENA.
Year: 2004.
University: PAÍS VASCO.
Place of defense: FACULTAD DE CIENCIAS QUIMICAS.
Place of preparation: FACULTAD DE CIENCIAS QUIMICAS.

Summary: Immediately after the description of the most important concepts in barrier properties, the ways to modify these properties, and experimental techniques, characterize the materials under study, with particular emphasis on the free volume of the same. In the final chapters there is a comparison between the techniques used to identify their barrier properties as well as the modification of different materials with the aim of improving them. It develops a detailed study of the transport properties of amorphous polyamide, amendment, either by adding antiplastificantes that reduce the volume free, in turn reducing the spread, either by nanoarcillas that reduced by an increase in tortuosidad in its path. This second option has also been applied to the polyamide 6 and polyethylene.

Author: Álvarez Gallego Yolanda.
Year: 2004.
University: VALLADOLID.
Place of defense: Facultad de Ciencias.
Place of preparation: GKSS Forschungszentrum (Geesthacht, Alemania) / ICTP-CSIC (Madrid).

Summary: In this work we have synthesized new poliimidas aromatic simultaneously containing imidazole groups sulfónicos and hetero, in the second part of the job, study the relationship between the properties of the synthesized polymers and functional groups present in them, the concentration and distribution of at the same polymer, and the proportion in which they find themselves. Rarely gets gather all the properties needed for advanced applications of membranes in a single material. The most common strategies are preparing membranes from blends of polymer dispersions or loads, usually inorganic, in the dissolution of the polymer. Another possible approach is to gather in one material with a combination of properties synthesizing copolymers, which is the resource used in this work. We have designed a family of poliimidas and copoliimidas carrying groups benzimidazole and sulfónicos which are characterized by originality of monomers elected. The development of experimental work has been structured into three chapters, each of which presents an introduction allusive to the nature of the same. The second chapter describes the synthesis and characterization of monomers and polymers prepared for this work. The third chapter is devoted to the properties of the new poliimidas, conducting a comparative study with the objective of making correlations estructura-propiedades of the series of polymers synthesized. Finally, the fourth chapter is devoted to the preparation of membranes in the form of film, from polymers prepared, and the evaluation of the same materials as exchange protónico for DMFCs.

Author: González Juárez Fernando.
Year: 2004.
University: VALLADOLID.
Place of defense: Facultad de Ciencias.
Place of preparation: Facultad de Ciencias.

Summary: The objective in this work is the collection and study of new films converters fluorescent light VIS-VIS for agricultural applications by incorporating fluorescent additives in polymer matrices based on polyolefins. This change in the typical formulations used not only affects their carcterísticas optics, but also to many other physical and chemical characteristics. For this reason the new materials have been evaluated through a variety of techniques in order to determine their suitability for application in agriculture, given that they must meet a number of prerequisites for transparency, stability and durability.

Author: ORTEGA RETUERTA ALVARO.
Year: 2005.
University: MURCIA.
Place of defense: Facultad de QUÍMICA.
Place of preparation: FACULTAD DE QUÍMICA.

Summary: THESIS ON THIS IS PRESENTS A STUDY OF SIMULATION BASED ON THE DEVELOPMENT OF BOTH APPROACHES THEORETICAL AS COMPUTACIONALES THAT WE ALLOW THE CALCULATION OF PROPERTIES DYNAMICS AND CONFORMACIONALES OF MACROMOLÉCULAS BIOLOGICAL ON DISSOLUTION. STUDY APPLIES TO ANY KIND OF STRUCTURE (RIGID, FLEXIBLE Ó SEMIFLEXIBLE) THE PARTÍCULA ADPOTE IN THE DISSOLUTION DEPENDING ON THE CONDITIONS UNDER WHICH IS FIND. THE OTHER PARTY, THE MODELING STRATEGIES TO BE DEVELOPED, ALLOW CHOICE OF POSSIBLE BETWEEN THE MODELS CUA L IS MORE ADEQUATE TO LEARN AND STRUCTURE INCLUDING PROPERTIES HODRODINÁMICAS SUCH AS COEFFICIENT DISSEMINATION TRASLACIONAL, COEFFICIENT SEDIMENTACIÓN, VISCOSITY INTRINSIC, TIMES RELAXATION OF PROPERTIES CONFORMACIONALES AS WELL AS THE RADIO TURNING. EXPERIMENTALLY IT POSSIBLE TO GET THE VALUE OF EACH ONE OF THE PROPERTIES REFERRED TO TECHNICAL DISPERSIÓN SUCH AS LIGHT IN THEIR TWO MEANS TO STATIC AND DYNAMIC, SEDIMENTACIÓN, VISCOSITY, ETC ... ESTUDIADOS SYSTEMS FOR THE CHECK OUR METHODOLOGY HAVE BEEN PROTEINS AND ACID NUCLEICOS MAINLY. THE INVESTIGATION IS FUNDAMENTA IN THE DEVELOPMENT OF COMPUTER PROGRAMS, REFERRED TO AS GENERICAMENTE HYDRO, DEVELOPED IN THE LANGUAGE PROGRAMMING FORTRAN AND BEGIN TO DEVELOPING IN THE RESEARCH GROUP FEW YEARS AGO. IN THE EVENT OF AGENDA HYDRONMR TO ALLOW CALCULATE PROPERTIES OF THE RELAXATION NMR AND THAT HABIA BEEN USED AND ABOVE, AN IMPROVEMENT HAS BEEN IMPLEMENTED IN TIMES OF CONSIDERABLE CPU, USING A METHOD FOR CALCULATING ALMOST IN PLACE OF RIGOROUS EMPLOYEE ABOVE, BUT NOT THE RESULTS ARE VEAN PRACTICALLY AFFECTED. THE CONTRIBUTIONS OF THIS MORE RELEVANT THESIS DOCTORAL HAVE BEEN THE DEVELOPMENT AND IMPLEMENTATION OF NEW PROGRAMS OF THE SERIES HYDRO. SPECIFIC MULTIHYDRO, MULTISUB AND MONTEHYDRO THAT EMPLEA A ALGORITMO MONTECARLO OF, AND OTHER PROGRAMS TO BE EMPLEAN FOR ESTIMATING THE STRUCTURAL PARAMETERS OF ANY KIND (SINGLE-HYDIT And MULTI-HYDFIT). BETWEEN THE SYSTEMS OF BIOLOGICAL TO BE APPLIED TO THE METHODOLOGY IS DEVELOPED IN THESIS, CABRÍA HIGHLIGHT THE INMUNOGLOBULINAS G AS EXAMPLE OF ANTICUERPO, RUBREDOXINA AS EXAMPLE OF PROTEIN AND OTHER SHORT OF DNA FRAGMENTS, AS ACID NUCLEICOS.

Author: CABIELLES ONDINA MIGUEL.
Year: 2005.
University: OVIEDO.
Place of defense: FACULTAD DE QUIMICA.
Place of preparation: FACULTAD DE QUIMICA.

Summary: The fly ash (CV) are solid waste produced during coal combustion. These wastes must be stored and / or reused. Storage of the VC has associated environmental problems. Reuse of VC is limited by the proportion of burnt (IQ) present. Therefore, the increase in the reuse of the CV and, consequently, a decline in its warehouse problems that entails, is associated with the separation and subsequent use of IQ. The burnt in fly ash have carbon content higher than 80% and a crystalline structure with a true three-dimensional structural system. Because of these characteristics, could be used as precursors for the preparation of synthetic graphite. The ultimate objective of this thesis is to prepare Doctoral materials grafíticos with structural characteristics suitable for use in industrial applications, using burnt in fly ash as precursors and by treatment at elevated temperatures. To carry out this work were selected fly ash (Bloomberg) from three thermal power plants. Fractions? 80 Â µ m in the CVO, known as fly ash of departure (CVP) were agglomerated with a vegetable oil used, obtaining samples with high content in IQ, called concentrates burnt (IBC). The IQ present at the PHC were separated by acid treatment, called those samples burnt separated (IQS). The PHC, the IBC and IQS have been characterized with regard to the quantity, composition and distribution of organic and mineral parties, and grafitizados in the interval temperaturas1800-2700 Â ° C, at different residence times. The materials grafíticos prepared from them have been characterized by XRD and Raman spectroscopy. Taking into account that a significant portion of the applications of synthetic graffiti are related to their electrical properties, it has been determined the electrical conductivity of the materials ready. The materials grafíticos prepared from burnt in fly ash, through treatment at temperatures 2400 Â ° C, have conductividades electrical and structural characteristics comparable to those for graffiti synthetic being used in various industrial applications. The reuse of these wastes as a precursor for the preparation of synthetic graphite is therefore planteable basis of the quality of the materials ready. The grafitización of burnt passes in two segments temperature. During the 1st segment there is a significant increase in the structural and electrical conductivity, forming, in some cases, structures grafíticas whose subsequent developments during the 2Â fourth segment is very limited. The influence of the residence time in the process of grafitización of burnt determined, in addition to the characteristics of the precursor, by temperature. As the temperature increases, the influence is less important, with a decrease in the time it takes for the material to reach its maximum degree of structural ordering. The mineral matter, including any of its constituent act as a catalyst for the grafitización of burnt. The catalytic effect of the mineral matter of burnt is the result of two conflicting processes. On the one hand, their presence increases the degree crystalline and electrical conductivity of the material, but on the other hand, reduces the temperature at which the material reaches a level close to the maximum lens made in each case. Accordingly, as of a given temperature and mineral content in the field, this catalytic effect is limited to promote 8 a crec 5ae imiento vegetative slow glass in the direction of the basal plane. In general, there is a relationship between electrical conductivity and order structural materials prepared from the burnt in fly ash. In those materials contained in mineral matter (inorganic) feeble, good correlations were observed between parameters crystalline, d002 and La, and Raman, ID / It, and the electrical conductivity. The presence of mineral matter in appreciable quantity affects far conductivity not only by the nature insulator / minus conductor of the minerals that form, but also because it alters the mechanical behavior of materials during powder compaction.

Author: ANDREU PUJOL ROBERT.
Year: 2005.
University: ROVIRA I VIRGILI.
Place of defense: FACULTAT DE QUIMICA.
Place of preparation: FACULTAT DE QUIMICA.

Summary: Currently in the field of polymeric materials is developing a new type of phenolic resins from 3,4-dihidro-2H-1, 3-benzoxazinas. The synthesis of these heterocyclic compounds takes place by the reaction of a phenol, a primary amine and formaldehyde. These monomers under the action of temperature or catalysts leading to polibenzoxazinas through a process of open ring. The resulting polymers are characterized by good mechanical and thermal properties, as well as excellent chemical resistance and UV radiation. The small change in volume experienced during the polymerization process together with its low viscosity facilitates processing make them very useful in the industry. Its low dielectric constant and low water absorption, make them especially used as electronic media. Finally, it should be noted that the presence of nitrogen and aromatic rings gives true nature retardante the flame. Normally curing benzoxazinas passes at high temperatures, usually higher than 200Â ° C. However, it is commonly used catalysts acidic nature to facilitate the process. Thus, the propagation mechanisms described in the literature for the polymerization of monomers of this type are of cationic nature and are based on the attack from positions nucleófilas ring oxazínico activated. The high temperatures required for thermal polymerization takes place can make coexist with the early stages of degradation. In addition, these temperatures cause the emergence of a large number of secondary reactions, among them include the formation of bridges novolaca and the reaction by other aromatic positions. All this gives rise to polymers great structural complexity. Most of the benzoxazinas used industry-wide to obtain materials are difuncionales, such as those arising from Bisfenol-A as giving rise to structures Interventions. This means that most studies so far refer to this type of compounds and not to benzoxazinas monofuncionales, so there is little information about the mechanism and structure of this type of polymer. For this reason, this paper has studied the formation of polymers through polymerization benzoxazinas monofuncionales prepared specifically for that purpose. Thus, the main objective has been to conduct a thorough study of the mechanism of polymerization. To do so, to be conducted by the synthesis of a family of benzoxazinas from different phenols and aromatic amines optimizing existing methods. First has studied the thermal polymerization of the monomers by differential scanning calorimetry, taking into account the influence of substituents with different electronic prepared on the aromatic rings. In addition, it has also been studied in thermal polymerization highly reactive monomers containing phenol and acid groups, noting the triggering effects which cause these groups on the polymerization. It has found a new starter system that has proved especially effective in curing solution of this type monomers. This system combines the action of boron trifluoride with alcohols, and allows polymerization proceeds under conditions softer following a primary mechanism of propagation different from those described thus far. It has been studied in detail the mechanism of polymerization in these conditions, which has been especially helpful to work with monomers marked with isotope deuterium. Finally, it has conducted a study of the thermal polymerization of monomers benzoxazínico 8 s who co 3b5 ntienen at once glycidyl groups in their structure, can reach two separate processes polymerization with the use of catalytic converters. This has enabled obtaining polyethers linear groups benzoxazina side may be entrecruzados at temperatures higher.

Author: MUJIKA GOROSTIDI JON IÑAKI.
Year: 2005.
University: PAÍS VASCO.
Place of defense: QUÍMICAS.
Place of preparation: UNIVERSIDAD VALENCIA.

Summary: This thesis concerns the study of the link amídico as a prototype for liaison peptídico. Specifically, the aim is to analyze the acceleration of its hydrolysis through torsion of the link, so that the work focuses on the study of the amide torsionada ( "Twisted Amdies"). First, work introduces the most important features of the link peptídico and why, as well as an explanation of the objectives of the work and why it matters. The author also briefly summarized the tools of Quantum Chemistry used during the investigation. In the second part of the thesis amides torsionadas are characterized; first quantifies stabilizing resonance that occurs in amides through rates of decolonization. This part of the job is a great interest because relates two concepts so far opposed, as are the theory "Atoms in Theory" the model of resonance. Next, we determine the theoretical value of pKa of amides torsionadas, concluding that the torsion has changed the basicida of the amide, increased its value pKa. In the third part of the thesis discusses the acceleration of hydrolysis of liaison amídico, comparing the potential energy surface (PES) of the amide torsionada with a planar maida similar. The study investigates different reaction mechanisms and the influence of a water molecule assistant. The most important conclusion is that the torque accelerates the reaction, even acceleration depends on several factors that are analyzed in detail in this investigation. Finally, the most important conclusions of the work are exposed, completing a detailed analysis of the consequences of structural and chemical torque.

Author: Álvarez Alcalde María de las Mercedes.
Year: 2006.
University: SANTIAGO DE COMPOSTELA.
Place of defense: Facultad de Ciencias de Lugo.
Place of preparation: Facultad de Ciencias de Lugo.

Summary: During the doctoral thesis "Structures Supramoleculares generated by bile acid derivatives and cyclodextrins" were conducted studies of various systems within prohibit the development of new supramolecular architectures, then shows the most significant results. There are several ways to modify the chemistry attached to bile acids, and perhaps most obvious, to change the nature of the various functions they hold. For example, we have transformed the group into a terminal acid and amino acid fosfónico, have generated various esters with alcohol steroid group were poliaminado and there have been various amides in the position C24 showing a great capacity gelling. However, it is possible to raise the issue in a different dimension as is the attempt to modify the relationship hidrofilia / hidrofobia between the two sides of bile acid, adding, for example, any group that spreads hydrophobic region hidrófoba of face ß. A priori, it would be easier to wait for auto-asociación of bile acid (or its salts) and the resulting reduction in the concentration of critical aggregation, cac. The two examples published so far with the group adamantilo and tert-butilfenilo located at position 3 of the steroid ring A, show a judicious choice. Both groups cac reduce colic acid (always viewed as a form of the sodium salt) between 30 and 40 times. But most importantly, the derivative with the group adamantilo generates laminar structures and the resulting tert-butilfenilo form tubular structures. With this idea, were synthesized two new fluorescent probes (Chapter IV) proved to unite through a link amide group pirenilo at position 3 of cholic acid and litocólico. For both probes, the relationship of vibrational signals (I1/I2) emission spectrum shows a clear dependence on the polarity of the solvent, following a pattern of behavior similar to the original fluorescent probe. This makes them useful for studying the polarity of the surrounding microenvironment as demonstrated in studies conducted with surfactants well characterized in the literature (SDS, CTAB, NaC and NaDC). Also, it is hoped, to synthesize two probes largest body, there is a considerable reduction in the lateral diffusion component in the study of membrane and complicating the analysis of experimental data. The opposite case, ie placed in the position 3 groups hidrófilos is explored in chapter III of the doctoral thesis. Apart from the physico-chemical studies of nature there are discussed, we must reflect an important fact here is that as the compound carrying acid succínico is very active against faloidina, toxin from the Amanita phalloides, and whose only known treatment is the liver transplantation. Thus, we find a new argument for continuing research and methodology undertaken. The observation and cited for the decrease in cac to insert groups hidrófobos suggested that an alternative to the extension of the region hidrófoba might be obtaining oligomers bile acid derivatives, primarily dimers and trímeros. In connection with the dimers, are three basic structures can be designed. In what follows, we understand by "tail" position 3 of the steroid ring and "head" side-chain wearing the carboxylic group. Therefore, the dimers sintetizables would cabeza-cabeza and cola-cola. Reference is made to the first chapter V of the thesis and the second in chapter VI. However, in order not to lose the role carboxyl, which logically defines the nature of bile acid, the bridge elected to the union of the two units bile must be such that with 8 serve ta 179b l function. To that end, it chose bridges dianhídridos (AEDT or piromielítico), and became the group acid C24 in an amino group. This will get surfactant structure gemini as they are known in the literature. Los valores de cac medidos fueron del orden de µM, dos órdenes de magnitud inferiores a los valores de cmc de las sales biliares de partida, ya sea el colato sódico o desoxicolato sódico según el caso. The relationship I1/I3 of pyrene in these systems is similar to the relationship of pyrene in the micelles colato or desoxicolato sodium, and it is concluded that pyrene is in an environment similar polarity. Surface tension measures undertaken show two points clear break in the slope of the experimental points. We conclude that when the gemini dissolves in water, the molecules are located at the interface aire-agua in a provision V (the area per molecule of surfactant at the interface is about 100? 2). In the absence of inert salts added, gemini are located at the interface in the form of V with the hydroxyl groups headed into the V stabilizing the structure through hydrogen bond intermoleculares. In the presence of other salts (eg, in a regulatory dissolution) area per molecule is reduced to 30? 2, corresponding to the formation of multilayers on the surface. The introduction of a bridge rigid piromielítico between the two waste bile (desoxicólico) leads to vesicular structures with a size around the 100 nm at low concentrations (results obtained from images of Transmission Electron Microscopy and from experiences Light Scattering mode dynamic and static). The process is fundamentally entálpico. The aggregate initial rate structures are transformed into "worm" or cylindrical causing a change in the rheological properties of the solution, increasing the viscosity of the same, resulting finally mesofase nemática at relatively low concentrations, 5 mM. While some bile salts forming liquid crystals liotrópicos, gemini peculiarity of this is that this phase is obtained at concentrations much lower and in a way almost instantaneous. Studies of low-angle X-ray (SAXS) indicate a low order in the mesofase. The change of the residual bile (colic) leads to a process of aggregation different. In dissolutions concentration above the cmc, there are aggregates cylindrical and is not detected a change in the visual rheological behavior or a change anisotropic. The technique of Transmission electron microscopy has provided us with images where aggregates were observed cylindrical with a diameter of 20-30 nm and a length of 180-240 nm. It measures Light Scattering determined the number of aggregation of ~ 3000 units gemini. The aggregation in solution is controlled mainly by the factor entálpico. We synthesized two new dimers cola-cola acid derivatives 3ß-cólico and 3ß-desoxicólico. The assembly of the two units steroid was across the bridge bidentado AEDT. These molecules are characterized by double burden on the number of units steroid, located at the ends of each bile salt. The determination of the cmc at various temperatures has led to conclude that such dimers presents a model of aggregation micelar in which dominates the effect entálpico versus entrópico, dominant in the process of aggregation of bile salts natural. The hydrodynamic diameter of aggregates in solution of the two dimers is similar to bile salts of departure, ~ 3.2 nm. The dímero of desoxicólico presents a number slightly higher than the aggregation of derivative colic. Taking into account the scale of polarity of pyrene, new micelles presents an environment similar to the polarity of colato and desoxicolato respectively. Another peculiarity of these new dimers dictated by the bridge and pKa values of the same, two units lower than the values for carboxylic acids such as acetic acid, this leads us to believe that they can provide values cmpH low, encouraging solubility at pH between 5,5-7, pH value in the small intestine, which gives them certain biological perspectives. On the other hand, given the crucial importance in the evolutionary process of auto-reconocimiento, along the lines initiated by the group to study systematically the formation of hydrogen bond in the crystals of the four epímeros acid desoxicólico, has been a study similar to epímeros of ursodeoxycholic acid quenodesoxicólico and. The results are shown and discussed in chapter II. Nor do we have resisted introducing as part of this thesis, some results of the initial phase of the same referring to a derivative alquilaminado of ß-cicldoextrina (6 (6 aminohexanamido) -6-desoxi-ß-ciclodextrina). This system is a rare example of isomerismo "in-out", and can be considered another example of molecular machine, both of which lie at the heart of the Supramolecular Chemistry. This system is studied in Chapter VII of memory.