STRUCTURE OF INORGANIC COMPOUNDS

Author: COVELO RODRÍGUEZ BERTA.
Year: 2003.
University: VIGO [www.uvigo.es].
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: This paper has studied the interaction of the metal centers cobalt (II), nickel (II), copper (II) and zinc (II) with alfa-hidroxicarboxilatos derived from glycolic acid (H2G), lactic (H2L), metilláctico (H2mL) mandélico (H2M) and benzyl (H2B), as a contribution to understanding the behavior coordinativo in solid-alfa-hidroxicarboxilatos front of divalent metal ions, obtained at an early stage for the complex homolépticos. These complex formulas [M (HL ') 2] and [M (HL') 2 (H2O) 2], where HL 'is the ligand alfa-hidroxicarboxilato, have been characterized by elemental analysis, infrared spectroscopy and ultraviolet, measures magnetic moment at room temperature and in some cases by X-ray diffraction; also has been investigated its thermal behavior. Acids monodesprotonados acted as bidentados chelate using atoms as giving an atom of oxygen group carboxylate oxygen atom and the group hidroxílico, forming a ring chelate five members. In a second phase of work has been prepared complexes heterolépticos of alfa-hidroxicarboxilatos with ancillary ligands: imidazole (im), 2.2 '- and 4.4' -bipiridina (bipi, 4bipi) 1,10-fenantrolina (fen ), 2, 2'-dipiridilamina (dipiam) and 1,2-bis (4-piridil) ethane (bpeta) by reaction of alfa-hidroxicarboxilatos metallic with these ligands assistants, usually ethanol. In addition to the conventional synthesis method was tested method hidro-/solvotermal to obtain and crystallize these compounds. In the complex heterolépticos behavior was observed coordinativo of ligands alfa-hidroxicarboxilato very versatile. In addition to the usual behavior bidentado chelate already seen in the complex homolépticos, has been found in [Cu (HB) 2 (im) 2] .2 H2O how bidentado chelate involving the oxygen atoms of the carboxylate group resulting in a ring chelate four members. In other cases, which correspond to the general formula [M (HB) 2 (NN) 2], as ligands bencilato acted as monodentados joining through a carboxylate oxygen of the group. There have been some compounds in which the anion alfa-hidroxicarboxilato are as contraiones cation complex, for example in [Cu (fen) 3] (HB) 2.7H2O. Likewise alfa-hidroxicarboxilatos can act as ligands bridges leading to polymeric structures of the type 1 [Cu (HB) 2 (NN)] and in other cases, acting as bridges are ligands auxiliary linear type spacer N, N, example 1 [Cu (HL ') 2 (4bipi)]. In most cases delos polymeric structures are obtained via links hydrogen interactions aplilamiento *-* and / or CH ..* type interactions between aromatic rings. The complex herolépticos have also been characterized by elemental analysis, thermogravimetric analysis, spectroscopic methods, measures magnetic moment at room temperature and X-ray Diffraction of monocristal. The spectroscopic data and measures magnetic can predict the coordination geometry of the complex. The thermogravimetric analysis has determined the content of water molecules coordination and crystallization. It has made the determination and structural through X-ray diffraction for a large part of these compounds in which they analyzed the organization supamolecular. In the structural study has been possible to observe the resolution in several spontaneous chiral compounds: [Zn (HmL) 2 (H2O) 2], [Zn (HmL) 2 (im) 2], [Cu (HB) 2 (im) 2] .2 H2IO, [Cu (B) (fen) (H2O)] .2 H2O and 1 ([Cu (HG) (dipiam)]) (HG). In some cases in which acetate was used as a precursor cash has been obtained as a byproduct acetato-complejos without ligands alfa-hidroxicarboxilato and in other cases where they have spent halogenated solvents in the recrystallization have formed products in a halide joins the field of coordination. In these cases seem imperative prese 8 ncia of 1e9 alfa-hidroxicarboxilato to achieve crystallization of the corresponding product.

Author: ORTEGA SAN MARTÍN LUIS.
Year: 2004.
University: PAÍS VASCO [www.ehu.es].
Place of defense: FACULTAD DE CIENCIA Y TECNOLOGÍA.
Place of preparation: FACULTAD DE CIENCIA Y TECNOLOGÍA.

Summary: The mixed oxide with type structure perovskita double (A2BB'O6) show great interest from the point of view of science and technology because of the wide variety of properties they own. These include the magnetorresistencia at room temperature, high temperature superconductivity, the coexistence of ferromagnétismo and ferroelectricidad and their catalytic properties. In this report has exposed the synthesis, structural and morphological characterization, as well as magnetic and spectroscopic properties of a series of mixed oxide with type structure perovskita double as general formula is Sr2B1-xMgxTeO6 (B = Co2 +, Ni2 +, Mn2 + and Fe3 + and 0 minor x minor 1). All the compounds studied were obtained by the method of freeze-drying. Crystallographic The study was carried out by X-ray diffraction of neutrons on sample policristalina. The characterization espectroscópica has been carried out through espectroscopías UV-Visibles, EPS, fotoemisión, X-ray absorption MÃ ¶ ssbauer of 57Fe. The magnetic properties were studied by the techniques of magnetic susceptibility in ac and dc modes, specific heat and neutron diffraction at low temperatures. The structures of the phases are characterized by different systems rotations of octaedros BO6 and TeO6. Later phases of iron and nickel, this system is given by the relationship a0b-b- (space group I12/m1). The phases of cobalt and manganese, on the other hand, show a rotation system to + bb- (panel P121/n1). With the exception of iron phases, which show the presence of disorder and tellurium vacancies, all compounds showed a very high order in the positions By Te. Most of the studies show transicines structural oxides at high temperatures remain in the transition temperature lower the lower the distortion of the structure at room temperature. The spectroscopic study has led to the parameters cleavage field crystalline 10Dq of all cations B. These measures have also indicated that the compounds present high ionicidad and B cations are in the states of oxidation: Mn2 +, Co2 +, Ni2 + and Fe3 +. The most important magnetic interactions in all phases these are antiferromagnético, with temperatures order below 40K. There have been, however, important differences between the compounds, which are related to both the nature of the cation B, as to the degree of order between cations B and B '. Compounds with B = Mn2 +, Co2 + and Ni2 + presents complete order between the two cations and behavior antiferromagnético of long-range order. The magnetic structure of these phases is Type I. The compounds of iron, on the other hand, show a complex magnetic behavior, similar to that of a glass of spin caused by the presence of disorder and vacancies in the positions B. In this situation, there is a wide variety deposibles roads exchange interaction between the cations of iron that can be ferromagnetic or antiferromagnético, causing a sharp rise frustration and behavior type of spin glass.

Author: ROJAS DELGADO RICARDO.
Year: 2004.
University: CÓRDOBA [www.uco.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: The hidroxisales laminar Ni and Zn (LHSs- [Ni-Zn]) are composed of plates with a positive charge to be offset by the intercalation of anions, which share the space between two consecutive sheets with water molecules. These are strong anion exchangers and present products roasting interesting because of its high specific surface and scattering homogéneade the cationesque the form. We have synthesized LHSs- [Ni-Zn] acetate in interlámina and has studied both the structure of the blades hidroxílicas with the disposition of acetate anions in the interlámina. It was subsequently made by the interc; tmbiode these species with simple inorganic anions (chloride, bromide, carbonate), as well as with other larger, éomo polioxometalatos and complex AEDT. The LHSs- [Ni-Zn] are good exchanger in all cases, obtaining high rates of exchange, while especieintercaladadependetanto the synthesis method as pH employee. We have studied the variations in the structure of hidroxisales to intersperse these anions and their influence on propiedadesde solids obtenidos.La disposition of anions in the interláminadependede the naturalezadel anion. The stages have been identified which produces the thermal decomposition of solid and have been characterized solids obtained by calcining. The deshidroxilación of the sample of the loss of the lamellar structure of solids obtained little crystalline oxides of the metals present in the structure with potential applications catalytic. By increasing the temperature of calcination there is an increase in the crystallinity which identifies the various oxides obtained, in which there are solid solutions of different cations present.

Author: CARBAJO MORENO M. CARMEN.
Year: 2004.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD CC. QUÍMICAS.
Place of preparation: FACULTAD DE CC. QUÍMICAS.

Summary: The interest porous solids newspapers have awakened scientists from different areas has allowed the development of methods of characterization and processing of such materials and their use in various applications. Within this group, materials macroporosos newspapers (lower 5 nm diameter) are keen on its transport properties and their potential applications as a membrane processes adsorption separation, filtration or diffusion. A method for preparing periodic porous material is molded replica using colloidal particles as templates. In this paper, have been prepared porous materials newspapers, using as a template ópalos latex. We have prepared particles monodispersas with size between 280 nm and 780 nm and of different composition. The latex orders were obtained through different methods of disposing of the solvent from suspensions of colloidal particles. Ease of auto-ordenamiento of the particles depends on the load surface d hydration layer that provides the repulsive force within walking distance sufficient to maintain separate particles. The mineralization of voids interpartículares mold is infiltrating a precursor to dissolution by sol-gel processes giving rise to solid product. The oxides are obtained by heat treatment in which removes organic matter. It has studied the influence of factors such as the composition of the molds, the method of infiltration and conditions of synthesis (and pioneering nature of the solvent, concentration, catalyst) have on the microstructure of the oxide. We have found different types of micro-nanoestructura that can be associated with the reactivity of precursors and the nature of the groups surface of the particles that form the mold. The study of the thermal stability of the structures macroporous periodic it has been observed that in some cases after treatment at 1000Â ° C, although growth and solder crystals produced sintering, remains a certain order in the porous structure.

Author: FORTES REVILLA CARLOS.
Year: 2004.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: FACULTAD DE CIENCIAS.AUTONOMA DE MADRID.
Place of preparation: FACULTAD DE CIENCIAS DE LA UNIVERSIDAD AUTONOMA DE MADRID.

Summary: This thesis aimed at the design of different lime-based mortar for the Restoration of Cultural Heritage simulating those used since antiquity in Roman times and changing the parameters for dosage, and additive nature of the binder to get with mortars resistance and better than older properties. On the other side is impregnated with different treatments hidrofugantes to improve their resistance to external agents aggressive environment. Finally, we design a lime-based mortar and metacaolín because it is very interesting for Restoration, and does not exist in the market mejorandolo technologically with additives and dosifcaciones well as curing time and carbonation. Finally, developing a methodology for characterizing various spectroscopic techniques of products hidrofugantes applied mortars because of the vacuum that exists in this matter.

Author: Casas Cabanas Montserrat.
Year: 2006.
University: AUTÓNOMA DE BARCELONA [www.uab.es].
Place of defense: Institut de Ciència de Materials.
Place of preparation: Institut de Ciència de materials de Barcelona.

Summary: The electrode oxihidróxido nickel (NOE) has been used in energy storage devices since the beginning of s. XX and now its application domain is still extremely broad, ranging from batteries for portable devices up to the aeronautical and space applications or electric vehicle. However, due to its inherent complexity and the fact that its development has been largely based on empirical criteria today still do not have a full understanding of its mechanism of operation. This work focuses on the study of NOE, des a viewpoint implemented as essential in order to optimize the manufacturing process of industrial matéria active and understand mejr their microstructural characteristics and the influence of these in the electrochemical performance. First, have been studied individually in a pilot plant different stages of a process of synthesis industrial real comparing the characteristics of the final product with other active trading. The results have enabled propose changes in the industrial process synthesis resulting in a significant improvement in the performance of electrochemical active matéria ready. Secondly there has been a more fundamental research with the aim to conduct a rigorous study of various microstructural samples beta-Ni (OH) 2, both industrial and prepared to the laboratory, and to establish correlations between the microstructural characteristics and Electrochemical performance. Finally, in the last stage of this work has been studied transformation beta-Ni (OH) 2/beta-NiOOH and structure of the phase oxidized by powder diffraction and transmission electron microscopy.

Author: DOS SANTOS GARCÍA ANTONIO JUAN.
Year: 2006.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of preparation: FACULTAD DE CC. QUÍMICAS.

Summary: Recently there has been increasing research in the search for new materials with superconducting properties. Within these materials are available "rutenocupratos", in which there are two phenomena superconductivity and magnetism, which in principle are to be antagonistic. Here, in this research, has developed the synthesis and characterization of new materials similar to those mentioned, where cation ruthenium is replaced entirely by iridium. In the field of replacements, the partial replacement of cations forming the structure, in order to improve their properties has been really long. However, the total replacement is still an unexplored field, which is a primary aim of this research work. In the course of a collection of materials, new phases that have emerged, although in the beginning they were not the main aim of the thesis, have proved to be really interesting.

Author: GOMEZ ALCANTARA MARIA DEL MAR.
Year: 2006.
University: MÁLAGA [www.uma.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: We have prepared phosphonates metal, as both crystalline porous, resulting Transition metal di-, tri-and tetrvalentes and acid alquilfosfónicos funcionalizados and arilbisfosfónicos. For all of them, a study of the influence of the synthesis conditions as on their properties. For the hydrothermal method, varying pH and molar ratio M / P were obtained various carboxialquilfosfonatos metallic crystalline monophasic: Mn2II (OH) (O3PCH2COO) .1/2H2O, Mn2II (OH) (O3PCH2COO), MnII) O3PCH2-CH2COOH). H2O, MnIII (OH) (O3PCH2CH2COOH). H2O, Cr2III (OH) 3 (O3PCH2CH2-COO) .3 H2O, Al3 (OH) 3 (O3PCH2CH2COO) 2.3H2O and Pb2II (O3PCH2CH2COO) 2 (O3PCH2-CH2COOH) 2. The crystal structures of carboxietilfosfonatos of Mn and Al were determined using the method ab initio dust laboratory and synchrotron respectively, and refined for the Rietveld method, while the structure of the compound Pb was determined from diffraction data X-ray of monocristal. The carboxietilfosfonatos of Mn have a fabric sheet, the Al (III) and Pb (II) form laminar structures, pillars containing organic interlaminares, while the carboxietilfosfonato Cr (III) proved to be amorphous. The measures indicate that magnetic lso carboxietilfosfonatos of Mn (II) and Mn (III) are surrounded antiferromagnéticametne low temperature, whereas the Cr (III) has no magnetic transition due to the absence of a long-range structural order. To get new bisfofonatos metal was synthesized for the first time, the acid bisfosfónico 4 - (4'-fosfonofenoxi) fenilfosfónico, H2O3PC6H6O-C6H4PO3H2, whose crystal structure was determined from X-ray diffraction data of monocristal. It has obtained compounds Mn (II), Fe (III), Co (II), Ni (II), Cu (II) and Zn (II), mainly through hydrothermal synthesis, which examined the influence of initial pH dela and temperature. The corresponding chemical formulas found were: Mn2II (O3PC6H4OC6H4PO3) .1.5 H2O, FeIII (HO3PC6H4OC6H4PO3) .0.5 H2O, CoII (O3PC6H4OC6H4PO3) .2 H2O, Ni2II (O3PC6H4PO3). NH2O (n = 2.3), cu2II (O3P-C6H4OC6H4PO3) , Zn2II (O3PC6H4OC6H4PO3) and ZnII (HO3PC6H4OC6H4PO3H). The structures Cu2II (O3PC6H4OC6H4PO3) and ZnII (HO3PC6H4OC6H4PO3H) were determined using data from X-ray powder diffraction laboratory method used ab initio, to the compound of Cu, and by Rietveld refinement of the method, the derivative Zn. With the new acid 4 - (4'-fosfonofenoxi) fenilfosfónico and acid 4.4 '-bifenilen-bisfosfónico, H2O3PC6H4C6H4PO3H2, has been addressed, on the other hand, the preparation of phosphonates microporosos Al (III), La (III) , Ga (III), Zr (IV) and Sn (IV). The solvent, the initial pH, the ratio M / P initial method of synthesis and the addition of agents mineralizantes as HF has been fctores modified to, in each case, obtain products with high values of specific surface area and pore distributions narrow focus between 10 and 20A. The compounds (III) and Ga (III) just presented porosity, while derivatives Al acid bifenilenbisfosfónico showed BET surface values between 100 and 350 m 2 / g, but with wide pore distributions in the region of the mesoporos fundamentally. Derivatives of Zr (IV) and Sn (IV) on the other hand, are composed mainly microporosos with specific surfaces between 300 and 400 m2/gy distributions with maximum pore size between 10 and 20 A. In bisphosphonates for Zr (IV) synthesis solvotermales in the presence of HF and DSMO providing the best products, whereas in the 4 - (4'-fosfonofenoxi) fenilfosfonatos of Sn (IV) mixes alcohol / water favoring microporosidad. In recent material also seen 8 will be an au 555 ment average pore diameter grows to the size of the chain used alcohol, which indicates that it is possible to control the size of microporo from solvent. Finally, it has introduced acid fenilfosfónico, C6H5PO3H2, as an agent with each spacer acid bisfosfónico. The fenil-arilbisfosfonatos metallic obtained generally increase its surface regarding the compounds prepared with a single ligand, while the pore size distributions widen slightly. Representative samples of bisphosphonates porous showed a moderate acidity with 1-2 umol/m2 site acids. The main techniques empledas in caracterizaicón of compounds obtendios have been elemental analysis, ATD-TG, IR spectroscopy, diffuse reflectance, difracicón X-ray, microanalysis, electron microscopy, spectroscopy MAS-RMN and adsorción-desorciónde gas temperature constant.