Yes / UV/vis absorption titrations have been used to investigate the formation of H-bonded complexes between anionic H-bond acceptors (HBAs) and neutral H-bond donors (HBDs) in organic solvents. Complexes formed by three different HBDs with 15 different anions were studied in chloroform and in acetonitrile. The data were used to determine self-consistent HBA parameters (β) for chloride, bromide, iodide, phosphate diester, acetate, benzoate, perrhenate, nitrate, triflimide, perchlorate, hexafluorophosphate, hydrogen sulfate, methyl sulfonate, triflate, and perfluorobutyl sulfonate. The results demonstrate the transferability of H-bond parameters for anions between different solvents and different HBD partners, allowing reliable prediction of anion recognition properties in other scenarios. Carboxylates are the strongest HBAs studied, with β parameters (≈ 15) that are significantly higher than those of neutral organic HBAs, and the non-coordinating anion hexafluorophosphate is the weakest acceptor, with a β parameter comparable to that of pyridine. The effects of ion pairing with the counter-cation were found to be negligible, provided small polar cations were avoided in the less polar solvent (chloroform). There is no correlation between the H-bonding properties of the anions and the pKa values of the conjugate acids. / Engineering and Physical Sciences Research Council (EPSRC).

Tesis por compendio / [ES] Las zeolitas son un material de aluminiosilicatos cristalinos microporosos extensivamente utilizados como catalizadores y tamices moleculares involucrados en procesos de separación. La mayoría de estos materiales son sintéticos, obtenidos en laboratorio mediante un proceso hidrotermal y barajando gran cantidad de variables como: relación sílice/agua, temperatura, tiempo, agitación y composición química. Cuando en la síntesis se introducen ciertas moléculas orgánicas, llamadas agentes directores de estructura, es más fácil entender y seleccionar moléculas específicas para dirigir la síntesis hacia una zeolita en particular. La situación ideal sería que cada agente director de estructura condujese la síntesis a una única zeolita, lo cual es poco probable que suceda, ya que, otros términos energéticos también juegan un papel importante, en particular el flúor y el aluminio. En esta tesis doctoral será acometido el estudio de estos tres factores: agente director de estructura, flúor y aluminio, además de su papel en la síntesis de zeolitas desde un enfoque químico-computacional. Proponiendo agentes directores de estructura más precisos para la síntesis de zeolitas, siendo sintetizadas de manera alternativa y/o más sostenible. / [CA] Les zeolites són un material d'aluminosilicats cristal·lins microporosos extensivament utilitzats com a catalitzadors i tamisos moleculars involucrats en processos de separació. La majoria d'aquests materials són sintètics, obtinguts en laboratori mitjançant un procés hidrotermal el qual presenta una gran quantitat de variables com: relació silici/aigua, temperatura, temps; agitació i composició química. Quan a la síntesi s'introdueixen unes certes molècules orgàniques, anomenades agents directors d'estructura, és més fàcil entendre i seleccionar molècules específiques per dirigir la síntesi cap a una zeolita en particular. La situació ideal seria que cada agent director d'estructura conduïra la síntesi a una única zeolita, la qual cosa és poc probable que succeïsca, ja que, altres termes energètics també juguen un paper important, en particular el fluor i l'alumini. En aquesta tesi doctoral es portarà a terme l'estudi d'aquests tres factors: agent director d'estructura, fluor i alumini, a més del seu paper en la síntesi de zeolites des d'un enfocament químic-computacional. Proposant agents directors d'estructura més precisos per a la síntesi de zeolites, sent sintetitzades de manera alternativa i/o més sostenible. / [EN] Zeolites are a microporous crystalline aluminosilicate material extensively used as catalysts and molecular sieves involved in separation processes. Most of these materials are synthetic, obtained in the laboratory by means of a hydrothermal process, and by shuffling a large number of variables such as silica/water ratio, temperature, time, agitation, and chemical composition. When certain organic molecules, called structure-directing agents, are introduced in the synthesis, it is easier to understand and select specific molecules to direct the synthesis towards a particular zeolite. The ideal situation would be for each structure-directing agent to drive the synthesis to a single zeolite, which is unlikely to happen, since, other energetic terms also play an important role, in particular fluorine and aluminum. In this doctoral thesis, the study of these three factors: structure directing agent, fluorine, and aluminum, and their role in zeolite synthesis will be undertaken from a chemical-computational approach. Proposing more precise structure-directing agents for the synthesis of zeolites, being synthesized in an alternative and/or more sustainable way. / León Rubio, S. (2023). Síntesis de zeolitas mediante agentes directores de estructura usando procesamiento de datos masivos (Big Data) [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/199280 / Compendio

Micelas são agregados coloidais formados por moléculas anfifílicas i.e., moléculas com uma região hidrofóbica e uma porção hidrofílica (surfactantes). Efeitos específicos de íons (EEIs) são observados em micelas iônicas, uma vez que as propriedades físico-químicas de agregado micelares, como tamanho e geometria, dependem da natureza do contra-íon. Diferentes ânions inorgânicos produzem alterações modestas nas propriedades de agregados micelares catiônicos, mas ânions orgânicos podem induzir efeitos mais pronunciados, como transições de forma do agregado ou separações de fase. Em sistemas micelares, os EEIs podem estar relacionados a: (a) diferenças na localização dos ânions nas micelas; (b) diferenças na hidratação micellar e de íons; e (c) possível formação de pares iônicos entre surfactantes e contra-íons na interface micelar. Diversos modelos foram desenvolvidos para descrever a formação e estabilidade de agregados micelares, considerando diferentes termos energéticos que possivelmente contribuem para a formação/estabilidade de micelas. Contudo, os termos descritos acima (a - c) geralmente não são incluídos nos modelos micelares. Assim, não deve ser possível predizer as propriedades de micelas catiônicas, usando os modelos atuais, caso o contra-íon seja pequeno, desidratado e capaz de formar pares iônicos, como o ânion trifluorometilsulfonato (triflato, Tf). Tendo isso em vista, determinamos as propriedades micelares de triflato de dodeciltrimetilamônio (DTATf) e comparamos com micelas análogas formadas por brometo, cloreto e metanosulfonato, visando identificar diferenças estruturais das micelas e suas origens. Para determinação de propriedades micelares, utilizamos uma série de técnicas experimentais: fluorescência resolvida no tempo, espalhamento de raio-X de baixo ângulo, condutometria, cinética química, ressonâncias paramagnética eletrônica e magnética nuclear e espectroscopia de relaxação dielétrica, entre outras. Observamos que o agregado de DTATf possui uma estrutura discoidal altamente empacotada, ordenada e desidratada e estas propriedades foram reproduzidos em simulações de dinâmica molecular. A análise do conjunto de resultados obtidos para DTATf demonstrou que a formação de pares iônicos na interface micelar induz severas alterações nas propriedades micelares, como a desidratação dos agregados. Os dados obtidos com DTATf demonstram claramente que, para um modelo teórico de sistemas micelares ser capaz de predizer propriedades micelares de diferentes agregados, a possibilidade de formação de pares iônicos na interface micelar e as interações específicas entre contra-íons e surfactantes devem ser modeladas. Adicionalmente, devido aos resultados aqui reportados e analisando outros sistemas interfaciais, propomos um papel mais fundamental para a água (interfacial ou de hidratação) nas propriedades micelares / Micelles are colloidal aggregates formed by amphiphilic monomers i.e., molecules with a hydrophobic and a hydrophilic moiety (surfactants). Specific ion effects (SIEs) are observed in cationic micelles, because the physicochemical properties of the micellar aggregates, such as size and shape, depend on the nature of the counterion. Different inorganic counterions lead to small changes in micellar properties of cationic aggregates, but organic counterions can induce more pronounced effects, such as shape transitions of the aggregates or phase separation. In micellar systems, the SIEs can be related with: (a) differences in the location of anions in micelles; (b) differences in the hydration of micelles and ions; and (c) possible ion-pair formation between surfactants and counterions at the micellar interface. Several models have been developed to describe the formation and stability of micellar aggregates, considering different energy terms that possibly contribute to the formation/stability of micelles. However, the terms described above (a - c) are generally not included in micellar models. Thus, it should not be possible to predict the properties of cationic micelles, using the current models, if the counterion is small, dehydrated and capable of forming ion-pairs, such as the trifluoromethylsulfonate anion (triflate, Tf). In this context, we have determined the micellar properties of dodecyltrimethylammonium triflate (DTATf) micelles and we have compared the results with similar micelles formed by bromide, chloride and methanesulfonate, aiming to identify their structural differences and its origins. To determine the micellar properties, we have used several techniques: time resolved fluorescence, small angle X-ray scattering, conductometry, kinetic assays, electron paramagnetic and nuclear magnetic resonances and dielectric relaxation spectroscopy, among others. We have observed that the DTATf aggregate presents a highly packed, ordered and dehydrated disk-like geometry and these properties were reproduced in molecular dynamics simulations. The analysis of the DTATf properties showed that the formation of ion-pairs at the micellar interface induces severe changes in micellar properties, such as micellar dehydration. The DTATf properties clearly demonstrate that for a theoretical model of micellar system to be accurate and general, the possibility of ion-pair formation at the micellar interface and the counterions-surfactant specific interactions must be modeled. Additionally, due to the results reported herein and by analyzing other systems, we suggest a more fundamental role of water (interfacial or hydrating water) in the micellar properties.

Micelas são agregados coloidais formados por moléculas anfifílicas i.e., moléculas com uma região hidrofóbica e uma porção hidrofílica (surfactantes). Efeitos específicos de íons (EEIs) são observados em micelas iônicas, uma vez que as propriedades físico-químicas de agregado micelares, como tamanho e geometria, dependem da natureza do contra-íon. Diferentes ânions inorgânicos produzem alterações modestas nas propriedades de agregados micelares catiônicos, mas ânions orgânicos podem induzir efeitos mais pronunciados, como transições de forma do agregado ou separações de fase. Em sistemas micelares, os EEIs podem estar relacionados a: (a) diferenças na localização dos ânions nas micelas; (b) diferenças na hidratação micellar e de íons; e (c) possível formação de pares iônicos entre surfactantes e contra-íons na interface micelar. Diversos modelos foram desenvolvidos para descrever a formação e estabilidade de agregados micelares, considerando diferentes termos energéticos que possivelmente contribuem para a formação/estabilidade de micelas. Contudo, os termos descritos acima (a - c) geralmente não são incluídos nos modelos micelares. Assim, não deve ser possível predizer as propriedades de micelas catiônicas, usando os modelos atuais, caso o contra-íon seja pequeno, desidratado e capaz de formar pares iônicos, como o ânion trifluorometilsulfonato (triflato, Tf). Tendo isso em vista, determinamos as propriedades micelares de triflato de dodeciltrimetilamônio (DTATf) e comparamos com micelas análogas formadas por brometo, cloreto e metanosulfonato, visando identificar diferenças estruturais das micelas e suas origens. Para determinação de propriedades micelares, utilizamos uma série de técnicas experimentais: fluorescência resolvida no tempo, espalhamento de raio-X de baixo ângulo, condutometria, cinética química, ressonâncias paramagnética eletrônica e magnética nuclear e espectroscopia de relaxação dielétrica, entre outras. Observamos que o agregado de DTATf possui uma estrutura discoidal altamente empacotada, ordenada e desidratada e estas propriedades foram reproduzidos em simulações de dinâmica molecular. A análise do conjunto de resultados obtidos para DTATf demonstrou que a formação de pares iônicos na interface micelar induz severas alterações nas propriedades micelares, como a desidratação dos agregados. Os dados obtidos com DTATf demonstram claramente que, para um modelo teórico de sistemas micelares ser capaz de predizer propriedades micelares de diferentes agregados, a possibilidade de formação de pares iônicos na interface micelar e as interações específicas entre contra-íons e surfactantes devem ser modeladas. Adicionalmente, devido aos resultados aqui reportados e analisando outros sistemas interfaciais, propomos um papel mais fundamental para a água (interfacial ou de hidratação) nas propriedades micelares / Micelles are colloidal aggregates formed by amphiphilic monomers i.e., molecules with a hydrophobic and a hydrophilic moiety (surfactants). Specific ion effects (SIEs) are observed in cationic micelles, because the physicochemical properties of the micellar aggregates, such as size and shape, depend on the nature of the counterion. Different inorganic counterions lead to small changes in micellar properties of cationic aggregates, but organic counterions can induce more pronounced effects, such as shape transitions of the aggregates or phase separation. In micellar systems, the SIEs can be related with: (a) differences in the location of anions in micelles; (b) differences in the hydration of micelles and ions; and (c) possible ion-pair formation between surfactants and counterions at the micellar interface. Several models have been developed to describe the formation and stability of micellar aggregates, considering different energy terms that possibly contribute to the formation/stability of micelles. However, the terms described above (a - c) are generally not included in micellar models. Thus, it should not be possible to predict the properties of cationic micelles, using the current models, if the counterion is small, dehydrated and capable of forming ion-pairs, such as the trifluoromethylsulfonate anion (triflate, Tf). In this context, we have determined the micellar properties of dodecyltrimethylammonium triflate (DTATf) micelles and we have compared the results with similar micelles formed by bromide, chloride and methanesulfonate, aiming to identify their structural differences and its origins. To determine the micellar properties, we have used several techniques: time resolved fluorescence, small angle X-ray scattering, conductometry, kinetic assays, electron paramagnetic and nuclear magnetic resonances and dielectric relaxation spectroscopy, among others. We have observed that the DTATf aggregate presents a highly packed, ordered and dehydrated disk-like geometry and these properties were reproduced in molecular dynamics simulations. The analysis of the DTATf properties showed that the formation of ion-pairs at the micellar interface induces severe changes in micellar properties, such as micellar dehydration. The DTATf properties clearly demonstrate that for a theoretical model of micellar system to be accurate and general, the possibility of ion-pair formation at the micellar interface and the counterions-surfactant specific interactions must be modeled. Additionally, due to the results reported herein and by analyzing other systems, we suggest a more fundamental role of water (interfacial or hydrating water) in the micellar properties.

A arilação seletiva de compostos orgânicos confere-lhes propriedades com amplas aplicações: em compostos de atividade biológica, inibidora da protease do vírus HIV-1, e de interesse como agroquímicos ou na engenharia de materiais. Em razão disso, novos métodos e reagentes tem sido desenvolvidos com essa finalidade. Sabe-se que a N-arilação de várias aminas, catalisadas por paládio, com haletos de arila e triflatos é tida como ferramenta importante a disposição do químico sintético. Do mesmo modo, publicou-se que a N-arilação de certos -amino ácidos por haletos de arila, procede-se facilmente quando catalisada por CuI. Alternativamente, a literatura cita outros métodos eficientes usando ácidos borônicos, compostos arilbismuto e compostos organochumbo. Neste trabalho foi estudada a arilação seletiva de ânions ambidentados pelo sal de iodo polivalente cloreto de difenil iodônio, em diferentes condições de reação, visando a otimização da síntese: 1) reação térmica (agitação magnética), sem catalisador, e em diferentes solventes, ou mistura de solventes; 2) reação sonoquímica, sem catalisador e em diferentes soluções; 3) reação térmica e sonoquímica na presença de catalisador CuCl (10%). Sacarinato de sódio, acesulfame de potássio, e ftalimida potássica foram escolhidos como ânions ambidentados derivados de sulfoimidas e imidas a serem arilados. No caso de N-fenil sacarina a quemiosseletividade e o melhor rendimento são observados com acetonitrila/água (1:1, v/v), sob refluxo para formação do par iônico intermediário (ou o iodano correspondente), seguido por fusão térmica na ausência de solvente. O acesulfame potássico, por sua vez, forneceu seletivamente produtos de N- ou O-fenilação, de acordo com as seguintes condições estabelecidas: 1) produto de fenilação por via térmica ou sonoquímica em etanol; 2) produto de O-fenilação, por via térmica ou sonoquímica em acetonitrila. A ftalimida potássica, na ausência de catalisador, é arilada em baixos rendimentos. A melhor condição de síntese é encontrada com acetonitrila e CuCl (10%), sendo 92% o rendimento por via sonoquímica e 78% por via térmica. A seletividade verificada foi analisada em termos das interações dos ânions ambidentados e dos solventes em questão. / The arylation of organic compounds gives place to a wide number of applications: concerning to their biological properties as HIV-1, protease inhibitor, as well as synthetic intermediates in pharmaceuticals, agrochemical and polymer chemistry. New methodologies and reagents have been developed as consequence of this. It is already known that N-arylation of several amines, catalyzed by palladium, with aryl halides and trifflates is a valuable tool to various reported organic synthesis. In the same way, it has been published that the N-arylation of certain -amino acids by aryl halides, proceeds smoothly when catalized by CuI. Alternatively, the literature reports other efficient methods using boranic acids, arylbismuth and organolead compounds. In the present work, it was studied the selective arylation of ambident anions by hypervalent iodine salts (chloride of diphenyl iodonium), in a different set of conditions, seeking the synthesis optimizations: 1) thermal reactions (silent mode, magnetic stirring), without catalyst, and, in different solvents or mixture of then; 2) sonochemical reactions, without catalyst, and in a different solvent composition; 3) thermal and sonochemical reactions carried out in the presence of (10%) CuCl as the catalyst. Sodium saccharinate, acessulfame K and potassium phthalimide were chosen as the ambident anions (derived from sulfonimides and imide functional groups) to be studied. In the N-phenyl saccharin case the chemioselectivity was achieved along the best yields when water/acetonitrila (1:1, v/v) solvent was employed in the step to form the ion pair (or the 3-iodane, intermediate), followed by the thermal fusion in the absence of solvent. The acessulfame K, for its turn, supplied selectively products of N- and O-arylation under the following established conditions: 1) N-phenylation in etanol through thermal and sonochemical approach; 2) O-phenylation product, in acetonitrila, by thermal and sonochemical method. Finally, arylation of potassium phthalimide with diaryliodonium is sluggish and gives low yields without catalyst. The best protocol to this synthesis was found with the solvent acetonitrile and (10%) CuCl catalyst addition, being 92% the yield of sonochemical reaction and 78% of the thermal one. The selectivity achieving was analyzed in accord with the solution interaction between the ambident anion and the solvent molecules.

Sur la base du principe de géomimétisme permettant l'utilisation de matériaux naturels comme le graphite, le diamant, le quartz a, la pyrite, etc. comme structures hôtes modèles, de nouvelles stoechiométries sont proposées. Leurs structures cristallines sont optimisées et discriminées sur la base de critères énergétiques, moyennant des calculs ab initio au sein de la théorie fonctionnelle de la densité (DFT). On proposera ainsi, par exemple XC3N3 (avec X = B, Al, P, Ga ou As), CN2 et C2N, ou encore SiNF. Les résultats obtenus ont permis notamment de proposer de nouveaux ultra-durs dans la classe de carbonitrures ternaires BC3N3, comme BC3N3 rhomboédrique qui présente un module de compressibilité de 358 GPa, un mécanisme de décomposition des carbonitrures (CVD) riches en azote initié la formation de N2 gazeux ou d'un radical cyanogène .C = N, ou enfin une nouvelle classe de matériaux, les silico-nitrofluorures dont l'archétype serait SiNF.

No description available.

No description available.

Les propriétés de transport et de diffusion e l'ion F ont été étudiées au sein de plusieurs séries de matériaux fluorés. La première partie de ce mémoire est consacrée à l'application du modèle des processus de clutérisation établi par J. M. Reau aux solutions solides de structure dérivée du type fluorine et comportant des cations substitutionels tétravalents. Cette étude a montré que ce modèle est un modèle général qui permet 'évaluer la nature et le nombre de porteurs de charge à longue distance en fonction de la composition. Les porteurs de charge dans les solutions solides M1xM"xF2+2x (M = Ca, Sr, Ba Pb ; M" = Th, U) ont été identifiés ux ions fluorure interstitiels F" et les processus de clutérisation ont été proposés au sein de ces solutions soles.<br />Les propriétés de transport et de diffusion de l'ion F - dans les phases du système BiF"-NH4F sont l'objet de la seconde partie de ce mémoire. Les phases de l'ammonium comparées aux phases homologues du rubidium compotent une plus grande mobilité de l'ion F- qui a été attribuée à des mouvements assistés de rotation/réorientation des ions NH4+. Cette hypothèse est confirmée par des investigations par RMN des phases du système BiF3-NH4F appliquées successivement aux noyaux 1H et 19F.

The main objective of nanotechnology is to build self-powered nanosystems that are ultrasmall in size, exhibit super sensitivity, extraordinary multi functionality, and extremely low power consumption. As we all know that 21st century has brought two most important challenges for us. One is energy shortage and the other is global warming. Now to overcome these challenges, it is highly desirable to develop nanotechnology that harvests energy from the environment to fabricate self-power and low-carbon nanodevices. Therefore a self-power nanosystem that harvests its operating energy from the environment is an attractive proposition. This is also feasible for nanodevices owing to their extremely low power consumption. One advantageous approach towards harvesting energy from the environment is the utilization of semiconducting piezoelectric materials, which facilitate the conversion of mechanical energy into electrical energy. Among many piezoelectric materials ZnO has the rare attribute of possessing both piezoelectric and semiconducting properties. But most applications of ZnO utilize either the semiconducting or piezoelectric property, and now it’s time to fully employ the coupled semiconducting-piezoelectric properties to form  the basis for electromechanically coupled nanodevices. Since wurtzite zinc oxide (ZnO) is structurally noncentral symmetric and has the highest piezoelectric tensor among tetrahedrally bonded semiconductors, therefore it becomes a promising candidate for energy harvesting applications. ZnO is relatively biosafe and biocompatible as well, so it can be used at large scale without any harm to the living environment. The synthesis of another transition metal oxide known as Co3O4 is also important due to its potential usage in the material science, physics and chemistry fields. Co3O4 has been studied extensively due to low cost, low toxicity, the most naturally abundant, high surface area, good redox, easily tunable surface and structural properties. These significant properties enable Co3O4 fruitful for developing variety of nanodevices. Co3O4 nanostructures have been focused considerably in the past decade due to their high electro-chemical performance, which is essential for developing highly sensitive sensor devices. I started my work with the synthesis of ZnO nanostructures with a focus to improve the amount of harvested energy by utilizing oxygen plasma treatment. Then I grow ZnO nanorods on different flexible substrates, in order to observe the effect of substrate on the amount of harvested energy. After that I worked on understanding the mechanism and causes of variation in the resulting output potential generated from ZnO nanorods. My next target belongs to an innovative approach in which AFM tip decorated with ZnO nanorods was utilized to improve the output energy. Then I investigated Co3O4 nanostructures though the effect of anions and utilized one of the nanostructure to develop a fast and reliable pH sensor. Finally to take the advantage of higher degree of redox chemistry of NiCo0O4 compared to the single phase of nickel oxide and cobalt oxide, a sensitive glucose sensor is developed by immobilizing glucose oxidase. However, there were problems with the mechanical robustness, lifetime, output stability and environmental adaptability of such devices, therefore more work is going on to find out new ways and means in order to improve the performance of fabricated nanogenerators and sensors.