CHEMISTRY (4)

Author: Morales Moreno Isabel.
Year: 2005.
University: MURCIA [www.um.es].
Place of defense: Universidad de Murcia.
Place of preparation: Facultad de Química (Universidad de Murcia).

Summary: The use of various electrochemical methods are of great interest for the analysis of the characteristics of real systems so diverse. These methods are an excellent tool for the characterization of these systems because they provide information on the thermodynamic behavior of the same and allow the determination of both constant speed chemical reactions as kinetic parameters relating to electrochemical process itself. The overall objectives of this report are summarized as follows: 1. Analyzing comparatively methods electrochemical voltamétricos with cronopotenciométricos to discern which of them is more suitable in each case, to show that the latter are an attractive alternative because they can be applied with equal ease and, in general, your answer can be expressed through mathematical equations simplest which allows for a simpler analysis of the same. 2. Deducting rigorous analytical solutions in order to study the evolution of the responses obtained for electrochemical systems are usually of a temporary nature to the corresponding stationary states. Obtaining an answer for stationary electrochemical behavior of various species allows the determination of the characteristic parameters of the same without intervening variable time, resulting in a much faster and simple processes that suffer these species. To make this possible is essential deduct strictly necessary and sufficient conditions to be able to introduce the simplified assumptions of steady state without losing information when studying chemical reactions kinetic processes coupled electrode. The first part of this report (Chapters 1-5) is devoted to the study of the pursuit of the twin goals earlier for charge transfer processes simple (Chapters 1-4) using different techniques cronopotenciométricas and comparing with the voltametría potential constant and with voltametría cyclical. In addition, we have included a study cronopotenciométrico deep catalytic mechanism (Chapter 5) through various techniques. The second part of the report is devoted to the study of the pursuit of both goals in voltametría and cronopotenciometría processes electrode with complicated chemical reactions. In this block, it appears mathematically how, while catalytic mechanism for a first or pseudo-primer order steady state is achieved regardless of the size of the electrode, ie only depends on the values of the kinetic constants of the chemical reaction without required use microelectrodos, for the mechanisms EC and EC first or pseudo-primer order the achievement of steady state passes through various stages, applicable to each other and to conventional electrodes microelectrodos before losing entirely dependence temporary and when it last happens, also loses kinetic information unless it is used microelectrodos whose dimensions conform to strict limits deducted in this report. This result seems to us essential because it is currently being used ultramicroelectrodos of different sizes to determine kinetic constants of the catalytic mechanisms, EC and EC under steady state conditions, without having yet been established limits of applicability of the equations for this stationary situation.

Author: ARIAS LOPEZ CARMEN.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: EDIFICIO DE BIOLOGIA. FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS. MODULO C X..

Summary: P53 is the most frequently mutated gene in human cancer, which is associated with adverse prognosis and resistance to therapy. Thus, an objective of this thesis was an analysis of the molecular mechanisms involved in the loss-of-function mutant protein found in p53, regarding its transcriptional activity, inducing apoptósis and DNA repair. Initially, we studied the response to cell damage of two mutations of p53 found in breast carcinomas, MDA-MB-231 (mutant contact p53R280K) and T47-D (mutant structural p53L194F). Both mutant p53 have lost the ability to induce stop cycle in G1, although the mutant p53L194F retains a degree of activity on gene transcriptional target of p53. Both mutant p53, p53R280K and p53L194F have lost apoptotic activity after its expression in cells deficient for p53. Surprisingly, there was a population in apoptotic cells MDA-MB-231 (p53R280K) in response to DNA damage. We conclude that there are mechanisms dependent on the cell type (MDA-MB-231), but independent of the presence of mutant p53R280K, which mediate the proteolysis of Bax, and in part to justify the differences observed. On the other hand, none of the mutants, p53L194F and p53R280K can transactivar gene proapoptótico bax, despite the mutant p53L194F, retains the ability to join your specific promoter. This loss of function partly explained the absence of apoptosis. In order to compare the differences transcripcionales p53 wild and mutant p53R280K and p53L194F, tests were conducted "microarray" of cDNA using the inducible system cells for the expression of p53 by tetracycline (Tet-Off). We found that the mutant p53 lost the expression of genes proapoptóticas and without emabrgo sobreexpresaban genes involved in cell cycle progression and DNA repair. These effects may mediate the selective advantage for survival of cells harboring mutations of p53. We decided to analyze the regulation of p53 one of the genes involved in repairs that had been indentificado in experiments "microarray", Rad51, and the role of p53 in homologous recombination. We have shown that p53 wild represses gene expression rad51 through direct binding element response to p53 present in the promoter of Rad51. Likewise, the damage to DNA favors both union p53 to the developer as declining levels of mRNA and protein Rad51. P53 wild also inhibits the formation of foci of Rad51 in response to the breakage of DNA double chain (DSBs), while the mutant contact p53R280K loses both the ability to suppress the expression of Rad51, as inhibition of the formation of foci the Rad51. Based on these results, we propose that the transcriptional repression of Rad51 is involved in the regulation of homologous recombination by p53, and thus the loss of this repression by the mutant p53 partly contributes to the malignant transformation that deriba a repair aberrant. Finally, in order to analyze the role of mutant p53 in the mechanisms of carcinogenesis start, we have considered the dialogue between the proteins p53 wild and mutant p53R280K and p53L194F. It expressed p53 wild and each of the mutants contenen a epítopo differential in cells deficient in p53, to follow up on the functional consequences of their interaction. We conclude that although both mutants, contact p53R280K and structural p53L194F confer varying degrees of heteroligomerización and stability p53 wild, the two induce a loss of apoptotic activity. Moreover, the imbalance in the activity transcri 8 pcional, 337 plus genes involved in the cycle and stability of p53, and diminished in the genes proapoptóticos may mediate the effect of dominant negative mutant of p53 on the role wild.

Author: DE CASTRO DE LA OSA SONIA.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: UNIVERSIDAD AUTONOMA DE MADRID.

Summary: Derivatives TSAO are a family of nucleoside highly funcionarizados inhibiting a potent and selective way the Tanscriptasa Reverse (IT) Virus Inmuno0deficiencia human type 1 (HIV-1, etiologic agent of AIDS). In this regard, despite its nature nucleosídica, behave like the group Specific inhibitors not Nuceleosídios (IENN) of this enzyme. However, derivatives TSAO show marked differences from the rest of IENNs in their behavior with respect to IT, which has become a family of compounds very peculiar and a useful tool for better understanding of HIV IT 1 and its inhibition. In this Doctoral Thesis have addressed various structural modifications in the ring 4-amino-g-sultona (or ring 4-amino-1 ,2-oxatiol-2 ,2-dióxido), structural feature more distinctive and less studied of derivatives TSAO. These changes have been made both in derivatives nucleoside TSAO like structures not nucleosídicas simpler. Within this overall objective has been referred to two key aspects on the one hand the study of the reactivity of the system enamínico this heterocycle, and on the other hand, testing of all biological compounds derived from a broad panel of viruses. To achieve these goals has been divided into three chapters. In Chapter 1 has been dealt with the development of new derivatives TSAO modified at position 4 "espiroanillo to enlist more active compounds, less toxic and more stable than 4" -oxalilaminoderivados TSAO previously prepared in our lab, obtaining a derivative he has shown an activity twice the prototype and of itself TSAO-m3T. In addition, it has obtained new derivatives TSAO modified at position 4 "espiroanillo which have low toxicity. Moreover, the introduction of urea groups in position 4" espiroanillo in derivatives TSAO has led to the discovery of the first examples of derivatives TSAO with activity against the replication of Human Cytomegalovirus. Also, since in the oxalilaminoderivados prototypes had noticed an unusual lability group 5'-tert-butilmdimetilsililo essential for the biological activity in the middle, has made a detailed study of the process of desililación, ran a mechanism for the same assistance intramolecular the amide group of the position 4. "There are very few precedents bibliographic hydrolysis groups sililo assisted intramolecular group neighbors, as our results complement previous studies and widespread. Chapter 2, has carried out a study the reactivity of the ring aminooxatioldióxido structures not nucleosídicas easily sintetizables, with the aim of generating structural diversity from the heterocycle and test compounds derived from a broad panel of viruses. In these studies have found that there are differences reactivity and in the ring 4-amino-g-sultona depending on the substituent of the position 5. Furthermore, despite the low nucleofília system enamínico ring, methodologies have been developed for obtaining new systems bicíclicos nitrogenous not described so far. Of these biciclos has emerged a new family of inhibitors not Nucleosídicos with activity compared to the replication of HIV-1. Chapter 3, starting with the skeleton heterocyclic of 4-ceto-g-sultona, obtained by reaction hydrolysis ring 4-amino-g-sultona, there has emerged a new family of compounds with antiviral activity compared to the replication of Human Cytomegalovirus and Varicella Zoster virus, and there have been changes at positions 4 and 5 of the heterocycle with the to establish relations biological structure.

Author: CABELLO GALISTEO FRANCISCO.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: INSTITUTO DE CATALISIS Y PETROLEOQUIMICA.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: This report is a study on the regeneration of oxidation catalysts (DOC) currently installed in passenger cars with diesel engines. To raise possible treatments reactivation of catalysts is a need to identify in advance the main causes that could cause its deactivation. Therefore, this paper presents an exhaustive study of characterization and action of catalytic activity of the DOC commercial. The objective is to understand the possible causes (chemical / physical and thermal), which originated its deactivation, as well as the relative impact of each on the catalytic action of DOC. He stressed the great difficulty in characterizing commercial catalysts, where the sample (radial and longitudinal coordinates) and the selection of the physical form of the same (dust, sheeting monolith or small cylinders) are keys to the analysis . The presence of cordierite (monolithic ceramic bracket) and pollutants singled studying characterization of the active phase (Pt) and the "washcoat" (composed primarily -Al2O3). First, it has come to characterize contaminants in commercial catalysts, which are drawn from different cars with mileage: 48,000 and 77,000 km in relation to another unused, used as a reference. The presence of phosphorous and sulfur contaminants out as majority of the DOC. These two elements react with inorganic "washcoat" causing AlPO4 and Al2 (SO4) 3, which causes the catalytic deactivation of catalyst. It has also detected the presence in smaller quantities of Si, Ca, Zn and Fe. As for the characterization of organic pollutants, it has been determined the presence of carbonaceous waste coke and low regard H / C. An interesting aspect is that the DOC commercial aging car presents significant longitudinal gradients (and to a lesser extent, radio) concentration of pollutants. The degree of deactivation of both catalysts used is quite similar, suggesting that the deactivation is not progressing as quickly from a certain mileage. Controlled aging tests in the laboratory have shown that thermal deactivation may have an impact on the catalytic activity, as long as the temperature reached by the monolith is sufficiently high. There has been regeneration of DOC through a commercial treatment washing with a solution of citric acid diluted after treatment in reducing atmosphere at 773 K. This procedure is able to decompose stages of AlPO4 and Al2 (SO4) 3 without removing components of the catalyst, producing its revival. Thus the effect is clear that the deactivation chemistry (due to the presence of phosphorus and sulfur) has on the DOC. In order to deepen the deactivation and reactivation catalytic have prepared catalysts Pt/Al2O3 in the laboratory as catalysts DOC model. First has studied the thermal deactivation due to sintering particles Pt. They have calcined catalysts at high temperatures, and verified its catalyst deactivation. Subsequently there has been redispersar particles of platinum by applying a treatment oxychlorination (small quantities of chlorine in a stream oxidant). The result has been a partial revival of the catalyst. The presence of Cl waste on the surface of the catalyst did not reduce the catalytic activity. There have also been employed systems Pt/Al2O3 catalysts DOC model to deepen the deactivation chemistry. These catalysts have been incorporated controlled amounts of sulfur and phosphorus to verify the decrease in the catalytic activity. Once it was applied methods revival by thermochemical treatment in reducing atmosphere and washed with citric acid, respectively. It has managed to deepen the knowledge of the process of decommissioning that the sulfur exerted on the catalysts Pt/Al2O3. The presence of aluminum sulfate formed in oxidizing conditions dis 8 minuye and 7f5 l specific area of support and modifies its acidity (initially Lewis type), emerging new centers type Brà ¸ nsted. This is related to a decrease in the adsorption capacity of CO and O2 on the Pt. However, differences in the crystallinity of the sulphates formed and concentration have not caused significant changes in the catalyst deactivation. It has been found that treatment reduction through flow diluted H2, at temperatures between 673 and 873 K, get revive largely the catalyst DOC. The addition of the phosphorus catalyst Pt/Al2O3 also leads to catalyst deactivation. He decrease their specific surface, but contrary to what is observed in the catalysts contaminated with sulfur, does not change the type of acidity of the medium. It should be noted that had detected the presence of aluminum phosphate low crystallinity. Again, the electronic effects are manifested in a decrease in the adsorption capacity of CO and O2. The citric acid washing with these catalysts contaminated with phosphorus produces catalytic its revival. It has been found the decline in phosphate groups surface after treatment, recovering completely specific surface. The revival can be interpreted in a catalytic partial recovery of the electronic properties of the active phase.

Author: GARCIA MARCO SONIA.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: Summary of the Report of Doctoral Thesis presented by Ms Sonia Garcia Framework entitled: "Scientific Contributions to Legal Framework Fertilizer of Quelatos Férricos: Analysis Cromatográfico. Effectiveness of Agronomique or p-EDDHA/Fe3 +". The iron chlorosis is a nutritional alteration as evidenced by the amarilleamiento intervenal of young leaves, while veins remain green (Chaney, 1984). It's an agricultural problem widespread mainly occurred in sensitive crops that grow in limestone or alkaline, where Fe oxides present low solubility (Lindsay, 1991). The use of synthetic ferrous chelates, specifically the so-called "phenolic", has proved to be the most effective way to correct this alteration when the crop is already in place (Sanz et al., 1992). Thus, increases the solubility of Fe and favors assimilation by the plant. Its main drawback is that the goods are very expensive, so that its implementation is only economically profitable crops with high added value, such as citrus, fruit, vegetable and ornamental. During the last fifteen years, the Spanish market has increased fivefold the number of commercial formulations of this type of fertilizer. In the current year (2005) are marketed 262 fertilizers such simple, with 78% derived from or oEDDHA. Besides Spain is the largest European consumer of these fertilizers is estimated in the 2004 consumption of 2,700 tons, which has been a disbursement to the farmers of 26 million euros. While knowledge of the factors affecting the effectiveness of the chelates has been studied in recent years, the lack of standardized analytical method for quantifying the real wealth of Fe chelate of these products has prevented the control of its quality, causing the lack of rigor in the data declared by the manufacturer (Hernández-Apaolaza et al., 1997; Álvarez-Fernández, 2000). To regulate this type of fertilizer, it has recently amended legislation on European fertilizers (OJEU, EC Regulation n fourth 2003/2003, 2003; OJEU, EC Regulation n fourth 2076/2004, 2004). It establishes a series of requirements for marketing and defines "chelate" as a soluble product obtained by the chemical combination of Faith with a chelating agent authorized. The product has to submit a minimum of 5% (w / w) of Fe-soluble, which, the fraction quelada must be at least 80%. It also has changed the list of permitted chelating agents, authorizing the use or pEDDHA present in the formulations business or oEDDHA/Fe3 +, and EDDHSA. In order to prevent any misuse of the term "Fertilizer EC, the European Commission proposes improved methods of analysis of existing fertilizers, which are set out in annexes and European standards recommended, as is the case for or chelates , oEDDHA/Fe3 + I oEDDHMA/Fe3 +, and adapt well to technological progress. It also proposes the elaboraración of new analytical methods for those fertilizers new entrants, as is the case with, or pEDDHA/Fe3 + and EDDHSA/Fe3 +. The updating and development of these methods is being carried out by the European Committee for Standardization (CEN), and in particular by the TC 260/WG 5 for "Fertilizer Micronutrient" from which our lab at the Autonomous University of Madrid form , conducting trials interlaboratorio. The technique of ion chromatography pair has been nominated as a highly effective technique for the determination of such chelates (Hernández-Apaolaza et al., 2000). This technique is based on the distribution of a solute ionized between two phases, polar and other apolar. The solute is ionized stable in the polar phase due to the effect of solvatación. If one adds to that stage another ion of opposite sign to the solute and possessing an important part organic, there will be a mating of cargo between amb 8 os ions 1ff8 (par-iónico). The resulting complex, having an organic part very voluminous, it will be easily absorbed by the stage apolar. In response to the mandate of the EC regarding chelating agents "phenolic" raised the following objectives: Objective 1: To validate through testing interlaboratorio a chromatographic method for par-iónico for analyzing ferrous chelates, or oEDDHA/Fe3 + I , oEDDHMA/Fe3 +. It conducted two trials interlaboratorio through which compared the method developed by Lucena and cabbage. (1996) and the European standard CEN EN 13368-2 (2001) for determining, or oEDDHA/Fe3 + I oEDDHMA/Fe3 +. The results obtained are decuce that the method of chromatography par-iónico developed by Lucena and cabbage. (1996), with some modifications, provides better value repeatability and reproducibility that the standardized method for determining or oEDDHA/Fe3 + I oEDDHMA/Fe3 +. That method of chromatography par-iónico has been proposed to be issued as standard European and replace the current IN 13368-2 (CEN, 2001c). Objective 2: Develop and validate new chromatographic methods to measure the Faith chelate by chelating agents or pEDDHA and EDDHSA present in commercial products. It proposes methods to determine the Faith chelate by chelating agents EDDHSA (monomer and condensation products) I p-EDDHA. Both methods use a column C-18 (150X3.9 mm and 5 m particle size), the flow is 1.5 ml / min and the injection volume was 20 l. The method for determining the Faith as chelate, or pEDDHA is isocrático and used as a mobile phase aqueous solution at pH 6 containing 35% acetonitrile and a concentration hydroxide tetrabutilamonio of 0005 M. The method for determining the Faith chelate as EDDHSA gradient and is used as a mobile phase two aqueous solutions at pH 6, containing one 35% acetonitrile and a concentration hydroxide tetrabutilamonio, 0005 M, and other, 75% acetonitrile and the same concentration hydroxide tetrabutilamonio. The chromatographic method developed for fertilizers EDDHSA/Fe3 + quantifies the Faith chelated by the monomer and condensation products that can be formed during the synthesis of the chelating agent. The chromatographic method developed for determining or pEDDHA/Fe3 + are well resolved peaks corresponding to or pEDDHA/Fe3 + and the diastereomers or oEDDHA/Fe3 +, but does not allow separate potential of diastereomers or pEDDHA/Fe3 + eluted into one. Álvarez-Fernández (2000) studied the quality of ferrous chelates phenolic marketed in Spain in the mid-90. This study showed that the market for these fertilizer products offered did not meet the requirements of the regulations in force at that time. During the years 2000 to 2004 has continued with the routine analysis of commercial products and the entry into force of the new European regulation has changed the requirements, so that another objective has been raised: Goal 3: To compare the quality of chelates ferrous phenolic marketed in the mid-90 with the analyzed after the introduction of the new European regulations and the publication of analytical methods. It has been found that the quality of products EDDHA/Fe3 + EDDHMA/Fe3 + and EDDHSA/Fe3 + has improved in recent years. Changing the rules on fertilizers and the emergence of standardized analytical methods have positively influenced the quality of these fertilizers, for the most part, meet the current regulations regarding minimum content required. The contents of Fe and Fe-soluble chelate is significantly higher in the samples tested during the years 2003 and 2004 that the products marketed until 1999. The relationship chelate Fe / Fe soluble has also increased in the commercial samples analyzed in recent years. In samples EDDHA/Fe3 + and EDDHMA/Fe3 + around 60% Fe is soluble chelate by distereoisómeros (racemate and meso), or oEDDHA I oEDDHMA. Yet there is still about a 40% Fe in these products would not be chelated by the chelating agent declared, but it might be linked to other isomers produced during its synthesis. If samples EDDHA/Fe3 + includes the contents of Faith chelated by the regioisomero or pEDDHA, the percentage of soluble Fe is known of their nature amounts to more than 80% on average, depending on the sample tested. In the case of samples EDDHMA/Fe3 +, if one includes the Faith chelated by the regioisómero or oEDDH4, 6MA, this figure rises to around 67%. For commercial samples EDDHSA/Fe3 + Fe content in certain chelate is twice if one includes the Faith chelated by the condensation products and the relationship chelate Fe / Fe is about 51% soluble. Due to good agronomic performance of the commercial products that contain EDDHA/Fe3 +, or chelate both isomer, oEDDHA as by or pEDDHA, this second isomer has been included in the list of approved chelating agents of the present Regulations. However, the causes of their effectiveness as a fertilizer alone, have not been investigated, so that another objective raised was: Objective 4: Study of effectiveness as a corrective to the chelate iron chlorosis, or pEDDHA / Fe3 +. From the results it appears that this iron chelate has certain advantages related to its agronomic speed of action is a more suitable substrate for the enzyme reductase chelate Fe, recovers quickly chlorosis in soybean plants grown in hydroponics and chelating agent is capable of solubilizar Fe native soil faster than other chelating agents, such as, or oEDDHA and EDTA. It explains the high efficiency of commercial fertilizers EDDHA/Fe3 + containing both regioisomers (or oEDDHA/Fe3 + I pEDDHA/Fe3 +). In them, the rapid action or pEDDHA/Fe3 + joins the lasting effect of, or oEDDHA/Fe3 +, so their combination is suitable for correcting iron chlorosis of crops. LITERATURE Chaney, R. L. 1984. Diagnostic practices to identify iron deficiency in higher plants. J. Plant Nutr.7 :47-67. Lindsay, W. L. 1991 Iron oxide solubilization by organic matter and its effect on iron availability. In Iron nutrition and Interaction in Plants. Eds. And Hadar Chen and Y. Pp 29-36. Kluwer Academic Publishers, The Netherlands. Sanz, M., J. Cavero and J. Abbey. 1992. Iron chlorosis in the Ebro river basin, Spain. J. Plant Nutr. 15 (10): 1971-1981. Hernández-Apaolaza, L.; Barak P. And Lucena, J. J. 1997. Chromatographic commercial determination of Fe (III) chelates of ethylenediamintetraacetic acid, ethylenediamine di (o-hydroxyphenylacetic) acid and ethylenediamine di (o-hydroxy-p-methyl-phenylacetic) acid. J. Chromatogr. In 789453-460. Álvarez-Fernández, A. 2000. Quality and efficiency of ferrous chelates (Fe-EDDHA, Fe-EDDHMA, Fe-EDDHSA and Fe-EDDCHA) com fertilizer. Doctoral thesis. Autonomous University of Madrid. Hernández-Apaolaza, L.; Álvarez-Fernández, A. And Lucena, J. J. 2000. Chromatographic commercial determination of Fe (III) -chelates. J. Plant Nutr. 23 (11 & 12), 2035-2045. OJEU (Official Journal of the European Union). 2003. Regulation (EC) N º 2003/2003 of the European Parliament and the Council of October 13, 2003 relating to fertilizers (N ° L 304 / 1, November 21, 2003). OJEU (Official Journal of the European Union). 2004. Regulation (EC) N º 2076/2004 of the commission on December 3, 2004 in which it is adapted for the first time Annex I of Commission Regulation (EC) N º 2003/2003 of the European Parliament and the Council of October 13, 2003, on fertilizers (EDDHSA and triple superphosphate) (N ° L 359/25, December 4, 2004). CEN. 2001. IN 13368-2: 2001 E. Fertilizers-Determination of chelating agents in fertilizers by ion chromatography-Part 2: EDDHA and EDDHMA.

Author: PRIETO SAUCO MARIA.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: Summary of the Report of Doctoral Thesis presented by Ms. Maria Prieto Elder with the title: "Growing and Using macronutrients in plant pepper (Capsicum annuum L.). Effects of climatic conditions and nutrition." Typically, in agriculture under cover nutrients are supplied with water. To prevent shortages, farmers use water and nutrients in excess. Even in the case of the use of recirculation systems, producers have to dump nutrients and water to the environment from time to time to prevent the dissolution nutritional imbalances in the root zone. As production systems current nutrients and water are always supplied in excess, the prospects for controlling and planning the growth of the crop and quality in production through an adequate supply of water and nutrients are not properly used by farmers. In production in greenhouses are lost each year approximately 120 kg N, 20 kg P 2200 L of water per hectare in the countries of northwestern Europe. By contrast, in the Mediterranean countries, where there are severe problems of water availability and salinization, the annual losses are approximately: 300-350 kg N, 125-300 kg P 600 kg Ky 3000-3500 L of water per hectare. As an example, in Spain it is estimated an annual loss of 16000 tons of nitrogen (with a total area of production of 50000 hectares), while in the Netherlands the loss is only 1200 tonnes of nitrogen (for a cultivated area of 10000 hectares. In greenhouses, compared to the open field in agriculture, climatic conditions and the root environment are much easier to control. Achieving control these parameters is necessary insight into the physiology of the crop, especially in the nutritional aspect. In order to determine the proper amount of nutrients that must be provided at all times is very important to the study of the composition and distribution of nutrients at different times fenológicos. addition is essential to know whether relationships exist between the amount of nutrients available and the different times of crop or different climatic parameters. The main objective of this work is to study the growth and nutrient uptake and distribution in the different organs of the pepper plant was chosen as representative of horticultural plant crops Mediterranean. were provide levels updated reference concentration of macronutrients (N, P, K, Ca and Mg) in the different organs of the plant for the new hybrid varieties and production at different times of the plant phenology pepper. Flames senior care levels K found. addition is determined that the most suitable conditions for the cultivation of pepper in hydroponics plant, crops are made in spring with a density of 6 stalks m2. are proposed equations for estimating biomass production and the amount of macronutrients it accumulates in the plant depending on the radiation received by the crop, and also verifies the validity of the equations of biomass production and accumulation of N in greenhouse crops. critical concentration values obtained Burns (1992 ) for young lettuces, expressed as% of the element in the dry, are: 4.8 for N, 5.4 for the K and 0.77 for Fr values from the literature were: 3,25-5 , 2 for N, 2,8-6, or for Ky. 0,37-0,75 to Fr latter are referred to the weight of the plant and Burns at the speed of growth. Concentrations critical to achieving the maximum growth or the same to achieve the highest growth rate. According to the author this difference in terms of reference, which might explain concentrations encountered criticism for N, K 8 P is 104e No slightly higher than those in the literature. The tests found that the removal of macronutrients (N, P, Ca and Mg) in pepper plant has a very quick response to the concentration of the element in all international bodies, especially root. restrictions on growth seen mainly in plants treated with dissolution nutritious without N after two weeks. Ky. Although, especially Ca, showed a lower resilience that the N and P, in general we can say that plants have a great capacity recovery after being subjected for several days to the interruption of a nutrient. Saure (2001) concluded in their review on the apical necrosis that when doing experiments to induce BER at low or zero concentration of Ca, the appearance of it does not reflect the status of commercial production since, usually there are no problems in providing adequate levels of Ca to crops. however, it is true that low concentrations of Ca in fruit show a high growth rate, although it is more indicative the K / Ch. Regarding the use of inhibitors of gibberellin biosynthesis to prevent the emergence of apical necrosis, it is stressed that in the same way that the C protects the integrity of cell membranes and this deficiency can cause stress in the plant, the lack of gibberellin can also induce stress (Saure, 1998). Moreover, Marschner (1983) points out that there is a need for high permeability of the membranes to allow the flow of solutes in tissues with rapid growth. addition growth a vigorous low concentrations of Ca does not necessarily mean an increase in the incidence of BER, as the loss of turgor observed in the initial stages of BER previously only happens if there has been a disintegration of the cell membranes in response to various stressors for the plant (high salinity, poor water, etc.). seems clear that it is necessary to study the relationship of the BER, not only with the Ca deficiency, but with the combination of various stressors. Despite this, Saure (1998) said that moderate levels of stress can increase tolerance of the plant to stress, through training of temporary acid abcísico (which is known as the "stress hormone"), thus reducing the activity of gibberellin and therefore promoting the amount of Ca. Despite some authors continue to believe that the main factor in triggering the BER is the concentration of Ca in the apical portion of the fruit (Taylor and Locascio, 2004), it seems reasonable to say that was not the Ca you can continue considering a primary or independent factor in the emergence of apical necrosis. Consequently control of the BER should not remain focused on maintaining high levels of Ca in the fruit as suggested, but to try to maintain a moderate growth of the stem, or try to avoid stress environmental sudden. moderate salinity levels do not cause a decrease in the perspiration of the pepper plants, but cause imbalances in concentrations cationic and distribution to the various organs of the plant. salinity caused by Mg cause greater imbalances and induces greater onset apical necrosis that salinity due to Na, whose effects are more easily paliables controlling climatic conditions.

Author: PEREZ FERNANDEZ RUTH.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS. DEPARTAMENTO DE QUIMICA ORGANICA.

Summary: The supramolecular chemistry has been defined as "the chemistry beyond the molecule", in which the association of two or more species by forces other than the covalent bond, leading to a supermolécula. It has also been called chemical receptor-sustrato, which recalls the "lock and key" enunciated by E. Fischer in 1894. This definition, more specifically, is based on the creation of a supermolécula consists of a substrate molecule and one receiving, possessing both centers complementary union, however, can not be applied to cases in which no two species can be distinguished. The process of molecular recognition plays a key role in most biological processes such as cell communication, catalysis or transport. Several biological systems (eg. DNA, proteins), built on the basis of the association of small components through non-covalent interactions are shown highly effective. The functional molecules require a high degree of complexity, difficult to get through covalent synthesis. For this reason, chemical, inspired by nature, are focusing their attention towards the use of non-covalent forces for the organization of supramolecular structures, so they can run their reactivity and control its function. The supramolecular chemistry has made significant progress, at the interface between biology and physics, and is therefore a highly interdisciplinary field. Among the potential groups to generate additional non-covalent interactions, Nature frequently used groups guanidinio for coordinating oxoaniones organic. The group guanidinio present in the side chain of arginine, how strong ionic pairs with carboxylate groups or phosphate in enzymes and antibodies, and is responsible for stabilizing tertiary structures in proteins via bridges saline internal carboxilatos. In this Doctoral Thesis, based on interactions guanidinio-oxoaniones, three basic themes in the development of supramolecular chemistry have been explored: molecular recognition (Chapter 2), auto-asociación (Chapter 3) and combinatorial chemistry dynamics (Chapter 4) . The molecular recognition not only seeks to achieve effective interaction between receptor and substrate, but also discover properties arising from the complexation, and therefore requires an effective and preorganización molecular design. In Chapter 2, the molecular recognition applies to the design of protease inhibitors, one of the key enzymes in the process of maturation of HIV-1. The inhibitors were designed based on a skeleton of guanidinio bicíclico chiral coupled with short peptide chains, imitating the sequence terminal protease, as well as remnants hydrophobic. as weak inhibitors of the active center. The absence of groups such as benzyl groups in protective compounds 2 and 3 leads to the loss of affinity for him monomer. The auto-asociación molecular studies systems capable of spontaneously generated, creating a well-defined architecture supramolecular self through its components under specific conditions. The information stored by these components allows to consider such systems as "supramolecularmente programmed." The synthesis of a molecule zwitterionica that could auto-asociarse in polar solvent is discussed in Chapter 3. Two synthetic strategies have been addressed in order to obtain the compound 34. One of them, based on microwave chemistry and supported reagents and 8 No políme bf3 ros, leads to complete the synthesis of the compound with a novel route symmetrical. Studies to determine the state of aggregation of the compound in solid and solution are currently underway. The third theme developed in this thesis deals with dynamic combinatorial chemistry, an emerging field that introduces concepts such as adaptation and evolution. Through self-organization through a selection process, in terms of thermodynamic equilibrium, generates a wide range chemical dynamics. This new field, the result of the merger between combinatorial chemistry and supramolecular chemistry, is oriented in Chapter 4 to the generation of receivers for the recognition of biomolecules such as DNA. Several derivatives guanidinio-tiol (51, 52, 46, 58, 59, 60 and 61), based on the exchange disulfide and tioester as reversible systems for the formation of dynamic combinatorial libraries (DCLs), were synthesized as builders of the same block while the compound 68 was synthesized as a template. Studies were performed with the pH composed 51, aimed to study formation of aggregates non-covalent in acid medium. The combination of the compound 51st with various ciclopéptidos, based on mono-and thiols, led to the acquisition of 72 and 74. The receiver 72 showed affinity for sulfate anion, while the receiver 74 possible recognition of the anion carbonate. This system is the first described so far based on ciclopéptidos with affinity for the anion. Mixtures dynamic oligomers were identified in the dynamic libraries formed by guanidinios bicíclicos chiral, although no amplification effects were observed with different oxoaniones tested as templates. Studies related to the conditions of formation of bookstores, as the tamponado used, are currently under development. Furthermore, the synthesis of tetraguanidinio 68 as a template to promote selective amplification species linear with respect to cyclical species was completed, and studies are carried out at present. DNA, one of the objectives bio-moleculares more interesting, it was used as template and may look at the generation of various species, to a certain extent detected by the analytical method used, which requires yet to be optimized.

Author: MONTEJO BERNARDO JOSE MANUEL.
Year: 2005.
University: OVIEDO [www.uniovi.es].
Place of defense: FACULTAD DE QUIMICA.
Place of preparation: FACULTAD DE QUIMICA.

Summary: Featured are two forms of hydrated azithromycin (a semisynthetic antibiotic) analyze the influence of solvents in the final product, its evolution with the humidity and temperature and structural similarities and their differences. This uses X-ray powder diffraction and monocristal, NMR, IR, DSC, TG, DTG, Karl-Fischer, gas chromatography and modeled theorists.

Author: GONZÁLEZ REDONDO JOSÉ RAFAEL.
Year: 2005.
University: POLITÉCNICA DE MADRID [www.upm.es].
Place of defense: E.T.S. DE ARQUITECTURA DE MADRID.
Place of preparation: ESCUELA TÉCNICA SUPERIOR DE ARQUITECTURA DE MADRID.

Summary: It looks, with considerable documentation, scientific and humane biography of Angel del Campo and Cerdán (Cuenca, 1881, Madrid, 1944), an eminent chemist Spanish from conideración of ignorance currently in force in science and the history of science Spanish Unique among the principal of "School Cabrera (Lab Investiigaciones Physics), which was first and pioneer in chemistry. It finds that, in the history of chemical Spanish reminded to be at least: a) be the first since the War of Independence, after the Restoration and Disaster 98, in the field of physical sciences Chemical makes chemicals "in Spain how European research program (spectroscopy), b) the first to be published with European scientists of the highest level (Georges Urbain), and c) make" father of chemistry Spanish " with the creation of teams (spectroscopy) and school (Analytical Chemistry) parallel to his life and his work, as could not be otherwise, the argument is also institutional history of physics and chemistry of the twentieth century Spanish - age silver, civil war and the first franquismo-. And serves as a context for the consideration of new aspects of the Physical Research Laboratory, the Spanish Association for the Advancement of Science, the Spanish Society of Physics and Chemistry, and so on. As well as to progress in the estudiso on his comrades, physics and chemistry, Blas Cabrera, Enrique Moles, Julio Palacios, Miguel Catalan and Arturo Duperier, and pharmacy, Jose Carracido Jose Casares, Obdulio Fernandez, Jose Giral and Antonio Madinaveitia. In short, this thesis is recovered memory of an eminent scientist Spanish forgotten, with an intensive and extensive study of his life and his work, establishing his snaps in the future of the history of science in Spain.

Author: ORTÍN AVILÉS MARÍA DEL MAR.
Year: 2005.
University: MURCIA [www.um.es].
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: FACULTAD DE QUÍMICA (UNIVERSIDAD DE MURCIA).

Summary: It has developed a new method of synthesis of benzo [b] acridinas, based on a reaction cicloadición [4 +2] intramolecular induced thermal C C-difenil-N- [2 - (2-propenil) phenyl] ceteniminas, where a function cetenimina serving as dieno totally carbonado and carbon-carbon double bond of sustituyente 2-propenilo plays the role of dienófilo. Likewise, it has carried out the heat treatment of N-[2 - (2-propenil) -1-naftil] ceteniminas C C-disustituidas and, depending on the substituents on the carbon terminal fragment cetenimina occurs her ciclación via a reaction Diels-Alder intramolecular to provide dibenzo [b, h] acridinas, and / or migration path [1.5] hydrogen from the carbon atom sp3's replacement 2-propenilo the central carbon atom fragment cetenimina , followed by a closing electrocíclico ring 6pi, to benzo [h] quinoleínas. It has been described for the first time the participation of ceteniminas processes radicalarios. It has conducted the addition intramolecular radical Benzyl generated from groups xantato and organic peroxides such heterocumulenos obtained via methyl radicals (indol-2-il) intermediate indoles replaced at position 2. Adding intramolecular to ceteniminas radicals Benzyl when they are generated from benzyl phenyl seleniuros by treatment with tris (trimetilsilil) silane in the presence of azoalcanos as AIBN, leading to 3-(1H-indol-2-il) propionitrilos, as a result of coupling crossed selective methyl radicals (indol-2-il) and the radical 1-ciano-1-metiletilo, from AIBN. These processes ciclación radicalaria are controlled by the effect of Radical Persistent. It has also been investigated adding radical ariloximetilo to ceteniminas, what it has been necessary to develop a new method of generating this kind of radical, which involves the reaction of (fenilseleno) methyl aril ethers with tris (trimetilsilil) silane / AIBN . The reaction of adding radical ariloximetilo to ceteniminas study has provided, through persistent radicals (2H-1 ,4-benzoxazin-3-il) methyl and in a process controlled by the Radical Effect of persistent, mixtures of 3-(2H -1, 4-benzoxazin-3-il) -2.2 -dimetilpropionitrilos and 2 - (2,3-dihidro-1 ,4-benzoxazin-4-il) -2-metilpropionitrilos. Reunification has been studied [1.5] sigmatrópico hydrogen and groups giving electronic [halogen, alkyl (aril) uncle, arilseleno, ariloxi and amino], from the carbon atom carbonílico until carbon central grouping cetenimina, N - (2-acilfenil) ceteniminas. It has been observed that such migration [1.5] takes place under conditions of thermal relatively mild reaction to the alkyl groups (aril) guy and arilseleno, while for the reunification [1.5] amino groups ariloxi and treatment is required strong heat. This migration [1.5], followed by the closure electrocíclico ring 6pi of cetena intermediate it has allowed access to a wide variety of 4-quinolonas doubly replaced carbon 3. The migration [1.5] Hydrogen N - (2-formil) phenyl ceteniminas where the group formilo is protected in the form of acetal or ditioacetal happened easily formed 4,4-etilenodioxi-3 ,4-dihidroquinoleínas and 4.4-etilenoditio-3 ,4-dihidroquinoleínas respectively, and involving cetenaacetales and cetenaditioacetales as intermediate reaction. The reaction mechanism for the conversion of N - (2-acilfenil) ceteniminas in 4-quinolonas been studied computationally level ab initio using N - (2-acil) vinyl ceteniminas as models structurally simpler. This study has been completed in a general mechanism in two phases, the first consisting of them in a grouping sigmatrópico [8 1.5] par 763 to provide a cetena intermediate, which in a second phase undergoes a closure electrocíclico ring 6pi. It has also been explored computationally an alternative way of ciclación of N - (2-acil) vinyl ceteniminas: closing electrocíclico ring 6pi leading to 1,3-oxazinas. It has been determined the nature pseudopericíclica of states of transition involved in the closure electrocíclico ring 6pi of cetenas intermediate in the transformation of N - (2-acil) vinyl ceteniminas in 4-piridonas, and the closure electrocíclico ring 6pi the N - (2-acil) vinyl ceteniminas leading to 1,3-oxazinas through the computation of NICS. It has carried out a kinetic study, based on data computing, the process of conversion of N - (2-acil) vinyl ceteniminas in 4-piridonas and 1,3-oxazinas showing that the 4-piridonas must be the thermodynamic control products and 1,3-oxazinas controlled products cinéticamente and, depending on the group giver on the role acilo of N - (2-acil) vinyl ceteniminas is required response times for very different in reaction mixtures end, prevail clearly 4-piridona on 1,3-oxazina.

Author: SUAREZ PEÑA BEATRIZ.
Year: 2005.
University: OVIEDO [www.uniovi.es].
Place of defense: E.U.DE INGENIERIA TEC. INDUSTRIAL Gijon.
Place of preparation: ESCUELA TECNICA SUPERIOR DE INGENIEROS DE MINAS DE OVIEDO.

Summary: This research work has been optimized microstructure of the alloy Al-Si 12 used to manufacture steps by lifting technique diecasting. The aim has been to design a metal alloy that allows manufactured in facilities that the company Thyssen Guss SA Possesses Mieres, steep elevation (P1000D2000) lighter and more resistant than those currently being produced (P1000M002), without modifying the facilities or the manufacturing process by injection pressure. The study was carried out in four stages: 1. Selection of materials. We examined five alloys Al-Si 12 from suppliers usual Factory. 2. Analysis of the effect of refining and modification on the alloy Al-Si 12. We studied the effect on the microstructure and mechanical properties to pull-alloy Al-Si 12 of the addition of afinantes (P and Ti) and modifier (Sr) at various concentrations. 3. Effect of refining and modification on pedaños lifting produced by the technique of diecasting from the alloy Al-Si 12. In the third phase was investigated the influence of the additions of afinantes and modifier identified in the previous stage on the steps of elevation produced by the technique of diecasting from the alloy Al-Si12. 4. Designing the optimal composition of the material for the manufacture of new rungs lifting lighter and less structurally reinforced that today. Tieniendo into account the results obtained in previous phases, in this final stage was designed composition of an alloy that would allow the manufacture of elevated levels of less identical but with enhanced mechanical properties that are now being manufactured.

Author: Gonzalez Campo Arántzazu.
Year: 2005.
University: AUTÓNOMA DE BARCELONA [www.uab.es].
Place of defense: Inst Ciencia de Materials.
Place of preparation: Universitat Autonoma de Barcelona.

Summary: This work has opened new strategies in the synthesis of large molecules and materials in the boron chemistry field. New carborane-containing carbosilane dendrimers (C-Si) and siloxane (O-Si) derivatives have been prepared. In addition, the incorporation of these clusters into Class II organic-inorganic hybrid materials have been studied. Dendrimers are described as macromolecules with interesting synthesis and applications due to their monodispersity and highly branched three-dimensional controllable structures, that provide a high degree of surface functionality. In this way, since carborane clusters have a great versatility, and thermal and chemical stability, their integration on the carbosilane dendrimers surface has been studied. In this respect, the functionalization of the periphery has been carried out using two different approaches, through a direct Cc-Si bond or introducing an alkyl spacer between these two atoms. The first alternative has allowed to obtain one family of dendrimers with four closo-carboranes on the periphery by two synthetic strategies: a) using hydrosilylation reactions with carboranilsilane compounds and the tetravinyl or tetraallylsilane as core, b) by nucleophilic substitution reactions of Si-Cl functions in cholorosilane dendrimers with the lithium salts of the carboranes. The integrated carborane reactivity has been studied towards nucleophiles and reducing agents. In all cases, the Cc-Si bond has been cleaved, except when Mg is used as reducing agent, from which the reduced nido-carborane is obtained. Subsequently, the expected anionic dendrimer has been isolated and characterized. In order to avoid the direct Cc-Si bond, new carborane-containing carbosilane dendrimers with a spacer between these two atoms have been developed. Thus, different approaches have been used in order to prepare several generations of dendrimers with different number (four or eight) of carborane clusters on the periphery. The subsequent reaction of these dendrimers with nucleophiles has allowed to obtain the corresponding polyanionic dendrimers with peripheral nido-carboranes. This opens an alternative way to prepare new metallodendrimers. In addition, carborane-containing siloxane derivatives have been also prepared. In a first approach several dimeric species with a Si-O-Si bond have been prepared in order to study its stability versus cluster's degradation reactions. The good results encouraged us to synthesize "in situ" carborane clusters functionalized silsesquioxanes using the hydrolysis-polycondensation of trichlorosilane and triethoxysilane precursors. This method has opened a new synthetic way to prepare carborane-containing siloxane dendrimers with silsesquioxane as a core. A family of carbosilane dendrons in which the carborane cluster is the core of the molecule have been prepared. These dendrons have been functionalized at the periphery with different groups which provide potential reactivity to the molecule. Additionally, the modification of the focal point or core has been also achieved by reduction of the carborane cluster using Mg. In parallel, Class II silicon-based organic-inorganic hybrid materials with carborane-containing units have been prepared from trichlorosilyl and triethoxysilyl-carborane-contaning precursors. The trichlorosilanes have allowed the formation of hybrid materials by either hydrolytic or non-hydrolitic Sol-Gel process, solid-state and carbodiimide Sol-Gel process. Two different triethoxysilane precursors have been used: a) precursors with a Cc-Si bond or b) precursor with an alkylic spacer between the Cc and the Si atoms. Several materials have been prepared by hydrolysis-polycondensation or Sol-Gel process using different experimental conditions. The Cc-Si bond cleavage has been observed when nucleophilic or basic conditions were used. The resulting solids have been studied in terms of porosity, specific surface area, level of condensation, macro- and microstructure and thermal stability. A thermal evolution of these materials at different temperatures have been carried out in order to study the possible carborane isomerization.

Author: López Sáez María Josefa.
Year: 2005.
University: MURCIA [www.um.es].
Place of defense: Facultad de Química.
Place of preparation: Facultad de Química, Universidad de Murcia.

Summary: This thesis focuses on the study of the reactivity of a series of complexes of ortho Palladium sustiuidos in front of a wide variety of molecules unsaturated: alquenos, alquinos, carbon monoxide, isocianuros, nitrilos, cianamidas, carbodiimidas, isothiocyanates and iminas. The thesis begins with a general introduction in the first chapter describes the synthesis of three 2-hidroxifenilcomplejos of Pd (II) by adding oxidizing reactions of 2-iodofenol on a complex of Pd (0) with dibencilidenacetona, Pd (dba) 2, in the presence of different ligands giving nitrogen. The second chapter describes the reactions of inserting 1,5-ciclooctadieno, dimetilmaleato, dimetil- and dietilfumarato and dimetilacetilendicarboxilato the link C-Pd some of the complex Pd prepared in Chapter 1, or other similar complexes prepared earlier the research group. It also describes the reactions of poliinserción of alquenos, namely 2,5-norbornadieno, norborneno and diciclopentadieno the link Pd-C (arilo) and Pd-C (acilo). The third chapter describes the reactivity compared with carbon monoxide and isocianuros of 2-hidroxifenilcomplejos of Pd, as well as one of the complex result of the insertion of dimetilmaleato, described in chapter 2. These reactions are obtained products insertion into the link Pd-C and products result of the displacement of ligands by isocianuro. The fourth chapter describes reaccioes insertion sequence isocianuro / alqueno and alquino / isocianuro. In the first obtaining inserting norbornadieno or norborneno the link Pd-C of iminoacilcomplejos of Pd, prepared earlier in the research group. In the latter an organic product is obtained by reaction with xililisocianuro a complex Pd result of the insertion of dimetilacetilendicarboxilato in bond Pd-C (arilo). The fifth chapter is the largest in the Doctoral Thesis, and describes the reactions of inserting nitrilos and cianamidas the link Pd-C a 2-hidroxifenilcomplejo of Pd. There was no precedent for insertion reactions of these molecules in links MF, M is a metal on the right side of the Periodic Table. Also be described in this chapter the reactions of various complex Pd with carbodiimidas, isothiocyanates and alenos. In reactions with carbodiimidas form complexes derived from the integration and addition of ligand. Chapter six describes the reactivity of various complexes PD versus benzophenone imina and acetimina, leading to the coordination of iminas to Pd, without the insertion occurs on the link Pd-C. Chapter seven contains the work carried out during a three-month stay in the research group of Dr. Robin B. Bedford, at the University of Exeter, during which collaborated in the study of the influence of the invitation estérico in geometry paladaciclos of triarilfosfito and its adducts of triciclohexilfosfina. Finally, Chapter 8 contains the pilot, which included copies of all spectra of IR and 1H and 13C-RMN. Chapter 9 contains the findings of the Doctoral Thesis.

Author: OSETE CORTINA LAURA.
Year: 2005.
University: VALENCIA [www.uv.es].
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: FACULTAD DE QUÍMICA.

Summary: The thesis is divided into two parts that coincide with the overall objectives of the work done: the study of corrosion processes of glass and glazed archaeological and characterization of drying oils, resins diterpénicas and acrylic resins used as materials filmógenos in restoring objects archaeological and glazed glass. The study of the corrosion processes in glasses and glazes archaeological has allowed the development of new methodologies based on the application of Microscopías Optics and Electronics and its coupling with a system of Image Analysis and the development of new analytical methods by Voltamperometría solid state for:-morphological characterization and chemistry of broken glass archaeological-species identification of Fe and Mn in the layers of glass corrosion-characterization and quantification of species cromóforas in glasses and glazes-tracking treatments restoration Likewise, analytical methodologies developed by Gas Chromatography and Pirólisis-Cromatografía of gases that have allowed:-characterization of materials filmógenos traditionally used in the restoration of glass and glazed-archaeological study of the influence of other substances in its analysis, the determination of the changes suffered by these materials in the processes of aging, cleaning treatments, the action degradativa of microorganisms or the effect of treatments biocides-characterization of materials filmógenos nature acrylic employees at present the restoration of glass and glazed-application of these methods in characterizing material filmógenos in real samples.

Author: Gregori García Juan.
Year: 2005.
University: VALENCIA [www.uv.es].
Place of defense: Facultat de Química.
Place of preparation: Facultat de Química.

Author: VICENTE ARROYO RUBEN.
Year: 2005.
University: OVIEDO [www.uniovi.es].
Place of defense: FACULTAD DE QUIMICA.
Place of preparation: FACULTAD DE QUIMICA.

Summary: This report describes the results of the study of the reaction of the ligand carbeno between exchange complex alquenilcarbeno Fischer chromium (0) and rhodium complexes (I). This study has permitted the development of new complexes carbeno Fischer of rhodium (I), as well as the development of interesting applications in the synthesis of organic compounds. The first chapter describes the process of exchange of ligand carbeno or reaction transmetalación, which has enabled the development of new complexes carbeno Fischer of cationic rhodium (I) and complex carbeno Fischer of rhodium (I) containing neutral ligands carbeno N-heterocíclicos. The second section presents the study of the reaction of the complex carbeno Fischer of rhodium (I) with alquinos, giving derivatives ciclopentenona through a reaction carbociclación [3 +2]. This result differs from that obtained by using the complex carbeno precursors chromium (0), which is a qualitative change in the reactivity of carbeno. Moreover, the reaction can be a catalyst when used alquinos electronically deficient. The third chapter is devoted to the study of the reaction of complex alquenilcarbeno Fischer with alenos. First, it describes the reaction of metátesis on thermal conditions and the absence of rhodium (I). Then, the process has been studied in the presence of a catalytic amount of rhodium (I) using alenos with different electronic properties. Under these conditions can be achieved very effectively and targeted a variety of 5-alquilidenociclopentenos highly replaced and funcionalizados, through a process carbociclación [3 +2]. Finally, in the fourth chapter describes three new multi reactions catalyzed by rhodium (I) between complex alquenilcarbeno Fischer and alenos. Thus, depending on the electronic nature of aleno can prepare various derivatives ciclohepteno, through a process ciclación [3 +2 +2]. In addition, a coupling reaction selective 4 components (ligand carbeno, 2 units aleno and CO).

Author: GONZALEZ ALVAREZ ALMUDENA.
Year: 2005.
University: OVIEDO [www.uniovi.es].
Place of defense: D.DE QUMICA ORGANICA E INORGANICA.
Place of preparation: FACULTAD DE QUIMICA.

Summary: The azamacrociclos have been widely studied as ligands in the context of Supramolecular Chemistry because of its ability to coordinate both cationic and anionic species. Moreover, despite the importance of quiralidad in biological systems, examples of receivers capable of carrying out a reconnaissance enantioselectivo of chiral substrates are scarce. In this memory, structured in four chapters, describes the synthesis of new poliazamacrociclos optically active and the application of some of these compounds in chiral molecular recognition processes. The first chapter is developing a synthesis quimioenzimática that accesses poliaza [n] ciclofanos optically active symmetry C2, which quiralidad stems from the presence of the structure of a fragment (R, R) -ciclohexano-1 ,2-diamina . In addition, it discusses the influence of aromatic spacer in the flexibility of the chain macrocyclic. The second chapter describes the isolation and amplification of different poliazamacrociclos optically active from a quimioteca combinatorial dynamics, using as a template different metallic cations. As units estrucjturales have been used fragments of cyclohexane-1 ,2-diamina and pyridine. It was also carried out a study of the effect staffing thermodynamic and the estructrura of the members of the quimioteca by mass spectrometry, NMR spectroscopy Vis-UV and of 1H, 13C and 113Cd. The third chapter uses one of the poliazamacrociclos prepared in Chapter 2 as an agent of displacement chirality for determining the enantiopureza different carboxylic acids by nuclear magnetic resonance. In chapter 4 is studied through valuations potenciométricas, mass spectrometry, nuclear magnetic resonance (dissemination measures) and molecular modeling the interaction between poliazamacrociclos obtained in Chapter 2 and various dicarboxilatos chiral. Significantly, one of the recipients tested showed a high enantidiscriminación with dianión malato. Moreover, it has tried to rationalize the results to propose a model of interaction that accounts for the selectivity observed in the formation of the corresponding supramolecular structures. Some of the results that constitute this report are listed in the following publications: -Selective host amplification from a dynamic combinatorial library of oligoimines for the syntheses of different optically active polyazamacrocycles, A. González-Álvarez, I. Alfonso F. López-Ortiz, A Aguirre, S. García-Granda, V. Gotor, Eur. J. Org. Chem. 2004, 1117. - Chemoenzymatic syntheses of ñnew optically active C2-symmetrical macrocyclic polyazacyclophanes, A. González-Álvarez, M. Rubio, I Alfonso V. Gotor, Tetrahedron: Asymmetry 2005, 16, 1361. - A highly enantioselective abiotic receptor for malate dianion in aqueous solution, A González-Álvarez, I. Alfonso P. Diaz, E. García-España, V. Gotor, Chem. Commun. 2006, 1227. - Highly diastereoselective amplification from a dynamic combinatorial library of macrocyclic oligoimines, A. González-Álvarez, I. Alfonso V. Gotor, Chem. Commun. 2006, 2224.

Author: MARCO ARIAS MARIA.
Year: 2005.
University: OVIEDO [www.uniovi.es].
Place of defense: D.DE QUIMICA ORGANICA E INORGANICA.
Place of preparation: FACULTAD DE QUIMICA.

Summary: This report reflects the results obtained in the course of investigating reactions yodofuncionalización of unsaturated organic substrates in aqueous media, including new processes of formation of carbon-carbon links. These changes require reversing the polarity of iodide present in the aqueous medium, or the transfer of ion yodonio center unsaturated, from iodine. In Chapter 1 describes synthesis biomiméticas of yodohidrinas and -yodocetonas from alquenos and ketones, respectively. Both processes are carried out in aqueous medium and have been promoted through the use of the system NaI/H2O2. These changes require the assistance of an acid to pass an effective, in a reasonable response time. In Chapter 2 presents the results in the synthesis of carbo- and hetero promoted by ions yodonio. In the first part of it is investigated the reactivity of compounds in water with structure -arilalquino front of the system NaI/H2O2/H + and elemental iodine face. These transformations lead to the synthesis regioselectiva of carbo- and hetero six links. The second part of chapter shows the results pertaining to the study of the reaction of 1,6-eninos with iodine in different solvents to generate yodocarbociclos on a regional and diastereoselectiva. The versatility of synthetic link IC allows to efficiently convert the proceeds.

Author: Pardo Botello Ma. del Rosario.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: Instituto de Ciencia de Materiales.
Place of preparation: Universidad Autónoma de Madrid.

Summary: Summary In this research work has been prepared thin films fotocrómicas via Sol-Gel based on the dispersion of molecules fotoactivas (naftopiranos and espirooxacinas). These films fotocrómicas to be irradiated with UV light (365 nm) get a strong color will depend among other things on the composition of the matrix ormosil or type of coloring. When this radiation ceases, films suffer a process of thermal clarified to regain its original state is not discolored. We have characterized the physicochemical properties of the parent ormosil using different analytical techniques as 29Si NMR, 13C NMR, FTIR, TEM, SEM and AFM. The use of modified matrix organic functional groups with R (type and quantity on the matrix) design allows the inner surface of the pores, in which the molecules fotocrómicas are encapsulated, thus enabling the controlled modification of the polarity of the environment pore and morphology. The properties fotocrómicas of the most important films, such as absorption spectra and kinetics clarified, are closely linked with the nature of the workplace pore, and thus can be controlled by the composition of the matrix and parameters of preparation and Sol-Gel trial. We have succeeded in controlling the position of the absorption band of the film in a state colored in a range of up to 56 nm for the same dye dispersed in different arrays. Moreover kinetics return to a non-colored molecule fotocrómica is strongly accelerated (t ½ to 6 times lower) when it is in an environment with higher organic matter (R groups with greater volume or more groups R ). It has used the technique elipsometría espectroscópica angle variable (VASE) to characterize the films fotocrómicas, showing as a powerful tool to study their optical properties and dynamics. In view of the possible applications of the materials fotocrómicos in the field of optics has studied the photostability of the molecules fotocrómicas face prolonged irradiation with UV light. The photostability of the dye molecules also depends on the pore environment in which they are located, can be up to 5 times more stable Matrix modified with phenyl groups (Ph) than those modified with ethyl groups (Et). With regard to the most applied this research, films fotocrómicas have been used as a means of holographic recording reversible, thereby recording networks diffraction to 275 lines per millimeter with a diffraction efficiency of 0.0057. These results are encouraging but the efficiency is still relatively low. In a future work seeks to maximize the efficiency of diffraction by controlling the properties fotocrómicas of films. The main results of this work have been published thesis in the journal Journal of Materials Chemistry and the Journal of Sol-Gel Science and Technology, and have been presented at a congress of Sol-Gel Materials as shown below: Articles M. Zayat, R. Brown and D. Levy, J. Mater. Chem., 2003, 13, 2899. R. Brown, M. Zayat and D. Levy, J. Mater. Chem., 2005, 15, 703. R. Brown, M. Zayat and D. Levy, J. Mater. Chem., 2006, 16, 1734. R. Brown, M. Zayat and D. Levy, J. Sol-Gel Sci. Technol., 2006, Accepted. Congress Photostability of a Photochromic Naphthopyran Dye Embedded in Sol-Gel Prepared Ormosil Coatings, R. Brown, M. Zayat and D. Levy. Poster presented at the 13th International Workshop on Science and Technology Sol-Gel (Sol-Gel 2005) Los Angeles (USA), August 2005

Author: FRESNO GARCIA FERNANDO.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: INST.DE CATAL.Y PETROL.(CSIC) FAC. CIEN..
Place of preparation: INST.DE CATAL.Y PETROL.(CSIC) FAC. CIEN..

Summary: There have been photocatalysts of TiO2 nanocristalino doped with Sn through a new synthesis method based on the reaction between TiCl4 and Ph3SnOH in CH2Cl2, leading to TiO2 amorphous with adsorbed species organiometálicas of Sn. The subsequent crystallization of this gives rise to solid materials late. Using Ph3SnOH recristalizado in the synthesis of amorphous materials formed by leading stages anatasa, rutile or both, depending on the conditions of crystallization without being detected a phase segregated from SnO2 (series TyH). On the other hand, cassiterite phase of SnO2 aparace when the amorphous is derived from Ph3SnOH not recristalizado (TiSnA1), or where such amorphous not wash with CH2Cl2 (TiSnB1). In the first case was identified Ph2SnO like the rest insoluble in the reagent business which gives rise to SnO2, while in the latter it comes from the deposition of sibproducto Ph3SnOH. The photocatalysts obtained have been characterized by various physicochemical techniques. In the series TyH observed different effect Sn4 + depending is in the anatasa or in the rutile. While the second is a possible replacement random Ti4 + by Sn4 + in the first results suggest some management cations Sn4 +. When coexist the anatasa and tuilo, effects are observed in both phases of doped. There are observed changes in the band gap regarding TiO2, but it is possible to the occupation of new levels in the electronic rutile doped. The sample TiSnA1 features similar to those of the T series, and their main difference is the presence of SnO2. The materials doped burnt lead to a faster Photocatalytic Degradation of metilciclohexano that fotocatalizador commercial reference Q25. In addition, the comparison with TiO2 not doped indicates that the addition of Sn significantly increases the photocatalytic activity of TiO2. The photocatalytic activity of these samples benefits besides the contact between anatasa and rutile and high crystallinity. The photocatalytic degradation of toluene, samples of the series TyHy the Q25 suffer a strong deactivation, unlike l catalyst TiSnA1 that will not shut off and leads, therefore, a faster reaction to the steady state other catalysts studied. It has linked the positive effect of SnO2 with a greater ability to retain water and a contact adecaudo between TiO2 and SnO2. We have also prepared photocatalysts of TiO2 nanocristalino doped with different amounts of Sn by the technique of microemulsiones reverse, with a good correlation between the calculated and obtained compositions. The characterization data indicate the presence of anatasa and rutile from a 3% atomic Sn, with the largest number of rutile by increasing the concentration of Sn. The results suggest a preferential concentration of Sn in the rutile respect to anatasa. Samples dopadas containing between 1 and 7% Sn showing increased activity that TiO2 in Photocatalytic Degradation of tricloroetilenio, with a maximum for the sample with a 5%, with 85% of anatasa and 15% rutile.