Tesis por compendio / [ES] La creciente urbanización e industrialización de las sociedades en las últimas décadas han provocado una alta demanda de energía. No obstante, mientras no se desarrollen fuentes de energía renovables que se constituyan como un reemplazo plausible de las actuales, la liberación de gases de efecto invernadero y sus consecuencias sobre el cambio climático difícilmente serán atajadas. Por ello, se está llevando a cabo una intensa búsqueda de energías renovables para un futuro inmediato. En los últimos años, la perovskita ha alcanzado una gran popularidad, centrando numerosos esfuerzos de investigación debido a sus propiedades ópticas y eléctricas únicas. Como por ejemplo su alto coeficiente de absorción y su alta movilidad de carga. Esta tesis comprende seis artículos científicos en torno a las perovskitas. Por un lado, 3 trabajos estudian los fenómenos ópticos que ocurren en el seno del material, con la finalidad de lograr una mejor comprensión de éstos. Puesto que el conocimiento de estos fenómenos ópticos a nivel individual (cristales aislados) permite modular y adaptar su síntesis y morfología para aplicaciones determinadas. Por otro lado, las perovskitas han sido implementadas en distintos dispositivos para su aplicación en tres campos: fotocatálisis, sensores y fotovoltaica. Por primera vez, se ha logrado utilizar este material para la obtención de hidrógeno llevando a cabo la reacción en fase vapor. Asimismo, diversas composiciones de perovskita se han usado para decorar grafeno y detectar niveles traza de Compuestos Orgánicos Volátiles (COV) como benceno y tolueno. Y finalmente se ha desarrollado una estrategia para insertar en la estructura de la perovskita moléculas orgánicas, de forma que se permite una ampliación de la fotorespuesta en el espectro visible. Por lo tanto, las perovskitas se han implementado exitosamente en aplicaciones de diversa índole, constituyéndose como un material prometedor y fácilmente adaptable a los distintos requisitos de cada campo de estudio. / [CAT] La creixent urbanització i industrialització de les societats durant les últimes dècades han provocat una alta demanda d'energia. No obstant això, fins que no es desenvolupen fonts d'energia renovables que puguen ser un reemplaçament plausible de les actuals, l'alliberament de gasos d'efecte hivernacle i les seues conseqüències sobre el canvi climàtic seran difícilment aturades. Per tant, s'està duent a terme una intensa cerca d'energies renovables per a un futur immediat. En els últims anys, la perovskita ha aconseguit una gran popularitat, centrant nombrosos esforços de recerca a causa de les seues propietats òptiques i elèctriques úniques. Per exemple, el seu al coeficient d'absorció i la seua alta mobilitat de càrrega. Aquesta tesi reuneix sis articles científics al voltant de les perovskites. Per una banda, 3 treballs estudien els fenòmens òptics que ocorren en el material, amb la finalitat d'assolir una major comprensió d'aquests. Donat que el coneixement d'aquests fenòmens òptics a nivell individual (cristalls aïllats) permeten modular i adaptar la seua síntesi i morfologia per a determinades aplicacions. Per altra banda, les perovskites han sigut implementats en diferents dispositius per a la seua aplicació en tres camps: fotocatàlisi, sensors i fotovoltaica. Per primera vegada, s'hi ha aconseguit utilitzar aquest material per a l'obtenció d'hidrogen duent a terme la reacció en fase vapor. Així mateix, diverses composicions de perovskita s'han utilitzat per a decorar grafè i detectar nivells traça de Compostos Orgànics Volàtils (COV) com benzè i toluè. I finalment s'ha desenvolupat una estratègia per a inserir en l'estructura de la perovskita molècules orgàniques, de forma que es permet una ampliació de la fotoresposta en l'espectre del visible. Per tant, les perovskites s'han implementat exitosament en aplicacions de diversa índole, constituint-se com un material prometedor i fàcilment adaptable als diferents requisits de cada camp d'estudi. / [EN] During the last decades, the growing urbanization and industrialization result in a significant need for energy. However, since feasible renewable energy sources should be further developed to replace the current energy source, the release of greenhouse gases and their climate change consequences are difficult to overcome. For that reason, the development of renewable energy sources has been attracting growing research efforts. Recently, perovskites gathered great interest owing to their outstanding optical and electrical properties. For instance, their high absorption coefficient and superior charge mobility. This thesis comprises six scientific articles about perovskites. On one hand, 3 works study the optical phenomena that occur within the material in order to achieve a better understanding. The deep knowledge of these optical phenomena's at the individual level (isolated crystals) enable the modulation and tuning of their synthesis and morphology to match specific applications. On another hand, perovskites have been implemented in several devices for their application in three research fields: photocatalysis, sensors, and photovoltaic. For the first time, this nanomaterial was successfully employed for obtaining hydrogen carrying out the reaction in the vapor phase. Likewise, several perovskite compositions have been used for decorating graphene and detect trace levels of Volatile Organic Compounds (VOC) as benzene and toluene. And finally, it has been developed a strategy to insert organic molecules in the perovskite structure, resulting in an enhanced photoresponse in the visible range. Therefore, perovskites have been successfully implemented in several applications, becoming a promising material and easily adaptable to the different requirements needed in each field of study. / Financial support from the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, SEV-2016-0683), Intramural CSIC project 201680I006, and Fundación Ramón Areces (XVII Concurso Nacional para la adjudicación de Ayudas a la Investigación en Ciencias de la Vida y de la Materia) is gratefully acknowledged. This research was financially supported by the Spanish Ministry of Economy and Competitiveness (Mineco) of Spain (TQ2011-26455)2, MAT2015-69669-P, and regional government grant PrometeoII/2017/026. This work was supported by Spanish ministry of Economy, Industry and Competitiveness (MINECO) through the projects TEC2015-74405-JIN, MAT2015-69669-P as well as the regional projects of both Provincia Autonoma di Trento (PAT) of Italy, through the call Grandi Progetti 2012: SIQURO and the Comunidad Valenciana of Spain project PrometeoII/2014/026. This work was supported in part by MICINN and FEDER via grants no. RTI2018-101580- B-I00, by AGAUR under grant. 2017SGR418. S. R.-B. thanks the Research Executive Agency (REA) and the European Commission for the funding received under the Marie Skłodowska Curie actions (H2020-MSCA-IF-2015/Grant agreement number 709023/ZESMO). R. G. A. acknowledges the FPI scholarship from MINECO MAT2015-69669-P. P. A. acknowledges the financial support from the Spanish Government through ‘Severo Ochoa” (SEV-2016-0683, MINECO) and PGC2018-099744-B-I00 (MCIU/AEI/FEDER) / García Aboal, R. (2021). Propiedades optoelectrónicas en perovskitas halogenadas y su aplicación en energía y sensores [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/175357 / Compendio

Nanomaterials have attracted great interest due to the unique physical properties and great potential in the applications of nanoscale devices. Two dimensional atomic crystals, which are atomic thickness, especially graphene, have triggered the gold rush recently due to the fascinating high mobility at room temperature for future electronics. The crystal structure of nanomaterials will have great influence on their physical properties. Thus, this thesis is focused on developing the methods to control the crystal structure of nanomaterials, namely quantum dots as semiconductor, boron nitride (BN) as insulator, graphene as semimetal, with low cost for their applications in photonics, structural support and electronics. In this thesis, firstly, Mn doped ZnSe quantum dots have been synthesized using colloidal synthesis. The shape control of Mn doped ZnSe quantum dots has been achieved from branched to spherical by switching the injection temperature from kinetics to thermodynamics region. Injection rates have been found to have effect on controlling the crystal phase from zinc blende to wurtzite. The structural-property relationship has been investigated. It is found that the spherical wurtzite Mn doped ZnSe quantum dots have the highest quantum yield comparing with other shape or crystal phase of the dots. Then, the Mn doped ZnSe quantum dots were deposited onto the BN sheets, which were micron-sized and fabricated by chemical exfoliation, for high resolution imaging. It is the first demonstration of utilizing ultrathin carbon free 2D atomic crystal as support for high resolution imaging. Phase contrast images reveal moiré interference patterns between nanocrystals and BN substrate that are used to determine the relative orientation of the nanocrystals with respect to the BN sheets and interference lattice planes using a newly developed equation method. Double diffraction is observed and has been analyzed using a vector method. As only a few microns sized 2D atomic crystal, like BN, can be fabricated by the chemical exfoliation. Chemical vapour deposition (CVD) is as used as an alternative to fabricate large area graphene. The mechanism and growth dynamics of graphene domains have been investigated using Cu catalyzed atmospheric pressure CVD. Rectangular few layer graphene domains were synthesized for the first time. It only grows on the Cu grains with (111) orientation due to the interplay between atomic structure of Cu lattice and graphene domains. Hexagonal graphene domains can form on nearly all non-(111) Cu surfaces. The few layer hexagonal single crystal graphene domains were aligned in their crystallographic orientation over millimetre scale. In order to improve the alignment and reduce the layer of graphene domains, a novel method is invented to perform the CVD reaction above the melting point of copper (1090 ºC) and using molybdenum or tungsten to prevent the balling of the copper from dewetting. By controlling the amount of hydrogen during the growth, individual single crystal domains of monolayer over 200 µm are produced determined by electron diffraction mapping. Raman mapping shows the monolayer nature of graphene grown by this method. This graphene exhibits a linear dispersion relationship and no sign of doping. The large scale alignment of monolayer hexagonal graphene domains with epitaxial relationship on Cu is the key to get wafer-sized single crystal monolayer graphene films. This paves the way for industry scale production of 2D single crystal graphene.

This thesis is concerned with the influence of nanoscale boundaries and interfaces upon the electronic processes that occur within the inorganic semiconductors. Inorganic semiconductor nanowires and their blends with semiconducting polymers have been investigated using state-of-the-art ultrafast optical techniques to provide information on the sub-picosecond to nanosecond photoexcitation dynamics in these systems. Chapters 1 and 2 introduce the theory and background behind the work and present a literature review of previous work utilising nanowires in hybrid organic photovoltaic devices, revealing the performances to date. The experimental methods used during the thesis are detailed in Chapter 3. Chapter 4 describes the crucial roles of surface passivation on the ultrafast dynamics of exciton formation in gallium arsenide (GaAs) nanowires. By passivating the surface states of nanowires, exciton formation via the bimolecular conversion of electron-hole plasma can observed over few hundred picoseconds, in-contrast to the fast carrier trapping in 10 ps observed in the uncoated nanowires. Chapter 5 presents a novel method to passivate the surface-states of GaAs nanowires using semiconducting polymer. The carrier lifetime in the nanowires can be strongly enhanced when the ionization potential of the overcoated semiconducting polymer is smaller than the work function of the nanowires and the surface native oxide layers of nanowires are removed. Finally, Chapter 6 shows that the carrier cooling in the type-II wurtzite-zincblend InP nanowires is reduced by order-of magnitude during the spatial charge-transfer across the type-II heterojunction. The works decribed in this thesis reveals the crucial role of surface-states and bulk defects on the carrier dynamics of semiconductor nanowires. In-addition, a novel approach to passivate the surface defect states of nanowires using semiconducting polymers was developed.

Combination of the compact but sterically flexible ferrocene scaffold with intermolecular binding potential and conformational variability of (2-hydroxyethyl)ammonium structural motif was utilised in the construction of solid crystalline materials. Crystallisation in systems containing ferrocenecarboxylic, 2-ferrocenylacetic, 3-ferrocenylpropionic, 3-ferrocenyl- acrylic, 3-ferrocenylacrylic, 3-ferrocenylpropiolic, ferrocene-1,1'-dicarboxylic or ferrocene- sulfonic acid with 2-aminoethanol afforded crystals of the corresponding salts. The resulting crystalline products were characterised with the usual methods (proton nuclear magnetic resonance, infrared spectroscopy, elemental analysis) and their crystal structures were determined by means of single-crystal X-ray diffraction analysis. The crystal structures of the salts mentioned above usually contain rather complicated two dimensional networks of charge-assisted hydrogen bonds. With the aim of studying potentially more simple hydrogen-bonded structures, additional crystallisation experiments were conducted in systems of ferrocenecarboxylic acid and 2-(methylamino)ethanol or 2-(dimethylamino)ethanol. These experiments yielded simple salt of the former amine and adducts of salts of both bases with ferrocenecarboxylic acid in the ratio of 1:1. The...

Cette étude porte sur des oxydes TiO2, SrTiO3 et SrZrO3 déficients en oxygène ou dopés par des ions de métaux de transition. Nous avons préparé des échantillons sous forme de polycristaux, de monocristaux et de films minces. Leurs propriétés structurelles, physiques et électroniques ont été mesurées à l’aide de techniques sensibles aux volumes (diffraction des rayons X, magnétométrie SQUID, résonance paramagnétique électronique) ou sensibles aux surfaces (spectroscopie de photoémission, spectroscopie d’absorption X). Les mesures de RPE et au SQUID permettent non seulement d’obtenir leurs propriétés magnétiques mais également la valence des ions Cr dopant. Nous avons ainsi pu établir les paramètres clés qui contrôlent la valence des ions chrome lors de la synthèse. Des phases secondaires telles que SrCrO4 peuvent se former quand les échantillons sont synthétisés dans des atmosphères riches en oxygène. Les propriétés de films SrZrO3 dopés au chrome sont également discutées. Leurs conditions de préparation influencent non seulement le comportement des ions chrome mais également celui de la commutation de résistivité. Ce dernier semble dépendre de la chimie de surface des films. L’accumulation d’ions Cr3+ au voisinage de la surface fournit une interface propre exempte d’oxydes non stœchiométriques. Cette terminaison nette de l’interface a pour résultat de bonnes performances de la commutation de résistivité. / In this study, the oxygen-deficient TiO2, SrTiO3 systems and transition metal ion (Cr or V) doped TiO2, SrTiO3 and SrZrO3 systems have been investigated. We prepared samples as polycrystals, single crystals and thin films for various desires. Their structural, physical and electronic properties were measured by bulk-sensitive techniques (X-Ray Diffraction, SQUID and Electro Paramagnetic Resonance) or surface-sensitive techniques (Photoemission spectroscopy and X-ray absorption spectroscopy). The measurement of SQUID and EPR showed not only their magnetic properties but also the valence state of Cr dopant. We verified the valence state of Cr ions in oxides and found the key parameters of sample synthesis which control the valence state of Cr ions. Segregated phases such as SrCrO4 were formed when the samples were synthesized under O2 rich environment. The surface properties of Cr doped SrZrO3 films are also discussed. We found the synthesis conditions which influence on not only the behavior of Cr ions but also the resistive-switching behaviors. Various resistive-switching behaviors seem to depend on the surface chemistry of films. We found that the accumulation of Cr3+ on film surface provides a clean interface without any non-stoichiometric oxides and that this sharp interface termination results in a good performance of resistive-switching.

In der vorliegenden Arbeit wird die Synthese neuartiger, polynuklearer Bismutoxido-Cluster sowie deren Potential zur Verwendung als Bausteine zum Aufbau organisch-anorganischer Hybridmaterialien beschrieben. Die molekularen Verbindungen werden nach partieller Hydrolyse eines basischen Bismutnitrats in DMSO erhalten. Durch Zugabe von Additiven wie Carbon- und Sulfonsäuren können funktionalisierte Bismutoxido-Cluster erzeugt werden, die eine gute Löslichkeit in organischen polaren Lösungsmitteln besitzen. Die Charakterisierung der Produkte erfolgte mittels Einkristallröntgenstrukturanalyse, NMR- und IR-Spektroskopie sowie ESI-Massenspektrometrie. Erste Untersuchungen zur Synthese röntgenopaker organisch-anorganischer Hybridmaterialien auf der Basis von Bismutoxido-Clustern und Methylmethacrylat wurden durchgeführt. Hierzu wurde der nanoskalige Bismutoxido-Cluster [Bi38O45(OMc)24] als anorganischer Baustein gewählt. Die Oberfläche des Bismut-Sauerstoff-Gerüsts dieser Verbindung ist mit Methacrylat-Liganden bedeckt, welche eine gute Löslichkeit vermitteln und durch ihre polymerisierbaren Funktionalitäten eine kovalente Anbindung z. B. an Vinylmonomere ermöglichen. Die radikalische Copolymerisation von [Bi38O45(OMc)24] mit Methylmethacrylat liefert transparente Komposite, die anhand von Festkörper-NMR-Spektroskopie, IR-Spektroskopie sowie TG- und DSC-Analyse charakterisiert wurden.

Im Rahmen dieser Arbeit wurden die Kondo-Gitter YbT2Si2 (T = Rh, Ir, Co) und CeTPO (T = Ru, Os, Fe, Co) untersucht. In diesen Systemen treten starke ferromagnetische Korrelationen der 4f-Momente zusammen mit ausgeprägter Kondo-Wechselwirkung auf, deren theoretische Beschreibung bislang sehr kontrovers diskutiert wird. Diese Arbeit liefert damit einen essentiellen experimentellen Beitrag zur Physik von ferromagnetischen Kondo-Gittern. So konnten qualitativ hochwertige Einkristalle von YbRh2Si2 hergestellt und erstmalig an einem Schwere-Fermion-System deren kritische Fluktuationen um den magnetischen Phasenübergang analysiert werden. Weiterhin konnte das bis dahin unverstandene Auftreten einer Elektron-Spin-Resonanz (ESR)-Linie in YbT2Si2 auf ferromagnetische Korrelationen zurückgeführt werden. Außerdem wurde mit CeFePO ein neues Schwere-Fermion-System mit starken ferromagnetischen Korrelationen entdeckt sowie mit dem isoelektronischen CeRuPO der seltene Fall eines ferromagnetisch geordneten Kondo-Gitters realisiert. / Within the context of this thesis the Kondo lattices YbT2Si2 (T = Rh, Ir, Co) and CeTPO (T = Ru, Os, Fe, Co) were investigated. In these systems strong ferromagnetic correlations of the 4f-moments together with pronounced Kondo interactions are present, whose theoretical description are pres-ently controversial discussed. Therefore, this work gives an essential experimental contribution to the physics of ferromagnetic Kondo lattices. The main results include the growth of high-quality single crystals of YbRh2Si2 and the first analysis of the critical fluctuations around the magnetic phase transition in a heavy fermion system. Furthermore, the unexpected observation of an electron spin resonance in YbT2Si2 could be ascribed to ferromagnetic correlations. Moreover, a new heavy fermion system CeFePO with strong ferromagnetic correlations was found and with the isoelec-tronic CeRuPO the rare case of a ferromagnetic Kondo-lattice discovered.

In der vorliegenden Arbeit wird die Synthese und Charakterisierung von chiralen prolylfunktionalisierten Farbstoffen vorgestellt. Als chromophore Schlüsselverbindungen wurden Nitroaniline aber auch größere push-pull pi-Systeme wie Schiffsche Basen, Azofarbstoffe und Merocyanine gewählt. Im Fokus dieser Arbeit stehen dabei deren solvatochrome Eigenschaften, pH-Sensitivität sowie mögliche Wechselwirkung mit Biomolekülen und verschiedenen An- und Kationen. Zusätzlich erfolgten Umsetzungen ausgewählter prolylfunktionalisierter chromophorer Bausteine zu Estern und Amiden. Der Einfluss des Prolylbausteins auf das im Festkörper ausgebildete Wasserstoffbrückenbindungsmusters wurde über Einkristallröntgenstrukturanalysen untersucht und nach der Graph Set Methode von Etter klassifiziert. Neben der Einkristallröntgenstrukturanalyse erfolgte die weitere Untersuchung der Festkörpereigenschaften mit Hilfe von UV/Vis- sowie NMR-spektroskopischen Methoden. Das solvatochrome Verhalten der prolylfunktionalisierten Verbindungen wurde mittels multipler linearer Regressionsanalyse gemäß der LSER- (linear solvation energy relationship) Beziehung nach den Ansätzen von Kamlet-Taft und Catalán beschrieben und vergleichend interpretiert.

Η παρούσα Διπλωματική Εργασία επικεντρώνεται σε προσπάθειες σύνθεσης και χαρακτηρισμού νέων συμπλόκων ενώσεων του In(III) με τη χρήση 2-πυρίδυλο οξιμών, αζολίων, 2-ακετυλοπυριδίνης υδραζόνης, δι-2-πυρίδυλο κετόνης και βάσεων Schiff ως υποκαταστάτες. Μελετήθηκε η επίδραση αρκετών συνθετικών παραμέτρων στη χημική και δομική ταυτότητα των προϊόντων. Οι οργανικοί υποκαταστάτες που χρησιμοποιήθηκαν και οδήγησαν σε αποτελέσματα παρουσιάζονται στο Σχήμα Ι. Σχήμα Ι. Οι συντακτικοί τύποι και οι συντομογραφίες των υποκαταστατών που χρησιμοποιήθηκαν στην παρούσα Διπλωματική Εργασία. Χρησιμοποιώντας ως ανόργανη πηγή Ιn(III) το InCl3 παρασκευάστηκαν τα ακόλουθα σύμπλοκα: [InCl3(H2O)(Mebta)2].Η2Ο (1.Η2Ο), (2-ΜeImH2)6{[InCl4(2-MeImH)2]}3[InCl6] (2), [InCl3(ΕtOH)(MepaoH)] (3), [CH3C(NH2)2][InCl4(NH2paoH].0.5MeCN (4.0.5MeCN), [InCl3{(py)2C(OEt)(OH)}].EtOH (5.EtOH), [InCl3{(py)2C(OH)2}].2MeCN (6.2MeCN), [InCl2(aphz)2][InCl4(aphz)]. Η2Ο (7.Η2Ο) και [In2Cl(saph)2(saphH)]. Et2O.EtOH (8.Et2O.EtOH). Οι δομές των ενώσεων 1-8 προσδιορίσθηκαν με κρυσταλλογραφία ακτίνων Χ μονοκρυστάλλου. Όλα τα σύμπλοκα χαρακτηρίσθηκαν με φασματοσκοπία IR, και επιλεγμένες ενώσεις με τεχνικές Raman, p-XRD, 1H NMR και Θερμοσταθμική Ανάλυση (TG). Τα φασματοσκοπικά δεδομένα εξετάζονται σε σχέση με τις γνωστές δομές των ενώσεων και τους τρόπους ένταξης των υποκαταστατών. Τα κέντρα InIII στις ενώσεις είναι 6- ενταγμένα με οκταεδρική γεωμετρία. Οι υποκαταστάτες Μebta και 2-ΜeImH συμπεριφέρονται ως μονοδοντικοί Ν- δότες, οι υποκαταστάτες MepaoH και NH2paoH ως Ν(2-πυρίδυλο), Ν(οξιμικό)- διδοντικοί χηλικοί και τα μόρια (py)2C(OEt)(OH) και (py)2C(OH)2 ως Ν,Ο,Ν΄- τριδοντικοί χηλικοί υποκαταστάτες. Ο υποκαταστάτης aphz συμπεριφέρεται ως Ν(2-πυρίδυλο), Ν(ιμινικό)- διδοντικός χηλικός, το ιόν saphH- ως Ο,Ν,Ο΄- τριδοντικός χηλικός και οι διδοντικοί υποκαταστάτες saphH2- γεφυρώνουν δύο κέντρα InIII μέσω δύο διαφορετικών αποπρωτονιωμένων ατόμων οξυγόνου. Πιστεύουμε ότι τα αποτελέσματα που παρουσιάζονται στη Διπλωματική Εργασία συνιστούν συνεισφορά στη χημεία ένταξης του ινδίου(ΙΙΙ), καθώς επίσης και στη χημεία ένταξης των οργανικών υποκαταστατών που φαίνονται στο Σχήμα Ι. / Our Diploma Work focused on the synthesis and characterization of new complexes of In(III) using 2-pyridyl oximes, azoles, 2-acetylpyridine hydrazone, di-2-pyridyl ketone and Schiff bases as ligands. The effect of several synthetic parameters on the chemical and structural identities of the products has been studied. The organic ligands used are shown in Scheme I. Scheme I. The structural formule and abbreviations of the ligands used in this Diploma Work. Using InCl3 as a source of inorganic ln(III), following complexes hve been prepared: [InCl3(H2O)(Mebta)2].Η2Ο (1.Η2Ο), (2-ΜeImH2)6{[InCl4(2-MeImH)2]}3[InCl6] (2), [InCl3(ΕtOH)(MepaoH)] (3), [CH3C(NH2)2][InCl4(NH2paoH].0.5MeCN (4.0.5MeCN), [InCl3{(py)2C(OEt)(OH)}].EtOH (5.EtOH), [InCl3{(py)2C(OH)2}].2MeCN (6.2MeCN), [InCl2(aphz)2][InCl4(aphz)]. Η2Ο (7.Η2Ο) και [In2Cl(saph)2(saphH)]. Et2O.EtOH (8.Et2O.EtOH). The structures of compounds 1-8 were determined by single-crystal X-ray crystallography. All the complexes were characterized by IR spectroscopy, and selected compounds by Raman, p- XRD, 1H NMR and thermogravimetric (TG) techniques . The spectroscopic data are discussed in terms of the known structures of the compounds and the coordination modes of the ligands. The InIII centers in the complexes are all 6- coordinate with an octahedral geometry. Mebta and 2- MeImH behave as monodentate N- donors, MepaoH and NH2paoH as N(2-pyridyl), N(oxime)-bidentate chelating ligands and (py)2C(OEt)(OH) and (py)2C(OH)2 as N,O,N΄- tridentate chelating ligands. The aphz molecule acts as a N(2-pyridyl), N(imino)- bidentate chelating ligand, the saphH- anion as an O,N,O΄- tridentate chelating ligand and each saph2- ligand bridges two InIII centers through a (different in each case) deprotonated oxygen atom. We believe that our results contribute into the chemistry of indium(III) and into the coordination chemistry of the ligands shown in Scheme I.

Gegenstand der vorliegenden Arbeit ist die Synthese und Charakterisierung neuartiger elektrophiler Barbiturate. In diesen Zielverbindungen sollte die kovalente Verknüpfung eines elektrophilen bzw. Lewis-aciden Zentrums mit einer Wasserstoffbrückensequenz realisiert sowie deren gegenseitige Beeinflussung untersucht werden. Im Mittelpunkt standen dabei Barbitursäure-funktionalisierte Triarylmethylium-Ionen sowie Merocyanine. Die Charakterisierung der synthetisierten Verbindungen erfolgte mittels NMR-Spektroskopie, Einkristall-Röntgenstrukturanalyse sowie solvatochromen Messungen. Besonderes Augenmerk lag auf der Wechselwirkung mit verschiedenen Rezeptoren über Wasserstoffbrückenbindungen, wobei sowohl die Anzahl als auch die Stärke der Wasserstoffbrücken variiert wurden. Die Reaktion der elektrophilen Barbiturate mit ausgewählten Nucleophilen wurde NMR- und UV/Vis-spektroskopisch verfolgt. In ternären Systemen bestehend aus Elektrophil, Nucleophil und Rezeptor wurde systematisch der Einfluss der Komplexierung über Wasserstoffbrücken auf die Gleichgewichts- und Geschwindigkeitskonstante der Elektrophil-Nucleophil-Rekombination erfasst. Daneben erfolgte die Bestimmung der Nucleophilie-Parameter substituierter Barbiturat-Anionen unter Berücksichtigung des ambidenten Verhaltens dieser Nucleophile.