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[pt] O magnetismo molecular tem despertado muito interesse devido a possível aplicação em componentes de materiais eletrônicos. Esses tipos de materiais podem ser criados através de compostos de coordenação, como os polímeros de coordenação, que têm a capacidade de serem materiais multifuncionais. Neste trabalho foram sintetizados 11 compostos inéditos, divididos em dois sistemas que diferem conforme a composição dos materiais. O primeiro sistema utilizou a mistura do ligante policarboxilato BTB e do ligante N-doador como phen e dmdpy para avaliar a influência desses ligantes auxiliares na estrutura e propriedades dos complexos. A família que utiliza fen como ligante auxiliar gerou dois polímeros de coordenação isomorfos 1D com Cu(2+) e Co(2+) como íons metálicos. Medições de EPR para o polímero Cu(2+) não mostraram quase nenhuma interação magnética entre íons metálicos. Devido ao fato de ambos os CPs serem isomorfos, as mesmas pequenas interações magnéticas eram esperadas para o Co(2+) CP, o que é um indicativo do possível comportamento da molécula magnética devido ao forte ZFS de cobalto. A medição da suscetibilidade magnética fora de fase mostrou o comportamento do nanoímã. Um tempo de relaxação de tensão no ponto de escoamento = 5,52(4) × 10(-7)s e barreira de energia de 12,1(3) K foram determinados para este complexo. A mudança do ligante doador de N de phen para dmdpy resultou em um dímero de Cu(2+)pentacoordenado, porém, como o ligante divergente para ambas as famílias era o mesmo, a pequena interação entre os íons cobre(II) foi obtida, como evidenciado por EPR e magnetização medições. O segundo sistema apresenta íons Ln(3+) com ácido cumarínico-3-carboxílico como ligante orgânico, onde duas famílias diferentes foram obtidas alterando a proporção de íons Ln e ligante. A primeira família 1D CP foi obtida com ambos os componentes na mesma proporção. Estudos magnetocalóricos foram realizados para o Gd(3+) e o valor de entropia magnética máxima obtido foi menor que o valor esperado. Para os CPs Tb(3+) e Dy(3+) apresentaram potencial como nanoímãs devido ao sinal obtido nas medidas magnéticas dinâmicas. Foram realizados estudos fotoluminescentes para CPs Eu(3+) e Tb(3+), onde foram estimados tempos de vida de emissão de 0,30 ± 0,05 ms e 0,13 ± 0,05 ms. A segunda família obtida apresentou proporção de Ln(3+) e 3-HCCA de 1:3, e resultou em um polímero de coordenação 1D, onde a extensão da cadeia polimérica teve o mesmo mecanismo. Foram realizados estudos fotoluminescentes para CPs Eu(3+) e Tb(3+), onde foi observado um aumento no tempo de vida da emissão de 0,30 ± 0,05 ms para 0,45 ± 0,05 ms para o derivado Eu(3+) devido à remoção de uma molécula de H2O coordenada ao íon európio. Este trabalho resultou, até o momento desta dissertação, na publicação de dois artigos científicos, além de outro adicional que está em processo de review. / [en] Molecular magnetism has created a lot of interest due to its possible application in components of electronic materials. These types of materials can be created through coordination compounds such as coordination polymers, which have the capacity to be multifunctional materials. In this work, we synthesized a total of 11 new complexes organized in two systems that differ according to the composition of materials. The first system utilized the mixture of polycarboxylate ligand BTB and N-donor ligand such as phen and dmdpy to evaluate the influence of these auxiliary ligands in the complexes structure and properties. The family utilizing phen as auxiliary ligand generated two isomorph 1D coordination polymers with Cu(2+) and Co(2+) as metal ions. EPR measurements for Cu(2+) polymer showed almost no magnetic interactions between metal ions. Due to both CPs being isomorph, the same small magnetic interactions were expected for Co(2+) CP, which is an indicative of possible magnetic molecule behavior due to cobalt strong ZFS. Out-of-Phase magnetic susceptibility measurement showed the nanomagnet behavior. A relaxation time of yield point stress = 5.52(4) × 10(-7) s and energy barrier of 12.1(3) K were determined for this complex. The change of N-donor ligand from phen to dmdpy resulted in a pentacoordinated Cu(2+) dimer, however, since the divergent ligand for both families was the same, the small interaction between the copper(II) ions was obtained, as evidenced by EPR and magnetization measurements. The second system presents Ln(3+) ions with Coumarin-3-carboxylic acid as the organic ligand, where two different families were obtained by changing the proportion of Ln ions and ligand. First family 1D CP were obtained with both components with the same proportion. Magnetocaloric studies were conducted for the Gd(3+) and the obtained maximum magnetic entropy value was smaller than the expected value. For the Tb(3+) and Dy(3+) CPs displayed potential as nanomagnets due to the signal obtained in dynamic magnetic measurements. Photoluminescent studies for Eu(3+) and Tb(3+) CPs were conducted, where 0.30 ± 0.05 ms and 0.13 0.05 ms emission lifetime was estimated. The second family obtained had a Ln(3+) and 3-HCCA proportion of 1:3, and resulted in a 1D coordination polymer, where the extension of the polymeric chain had the same mechanism. Photoluminescent studies for Eu(3+) and Tb(3+) CPs were conducted, where an increase in the emission lifetime from 0.30 mais ou menos 0.05 ms to 0.45 0.05 ms for Eu(3+) derivate was observed due to the removal of one H2O molecule coordinated to the europium ion. This work resulted, at the time of this dissertation, in the publication of two scientific papers, as well as a submitted paper that is currently under review.

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Chapter 1: Functional and Responsive Supramolecular Gels In this chapter ‘supramolecular gels’ derived from small organic molecules with molecular mass of typically less than 2000 daltons are discussed. Representative examples of various low molecular weight gelators based on their natural availability and also divergent functionalities are mentioned (Scheme 1). Scheme 1 Advances in the recent years have been very rapid in the field of supramolecular chemistry of gels giving rise to ‘Tunable responsive gels’. Control of the gel property in a reversible fashion has been the highlight of responsive gels. A few of the gels which are responsive towards various stimuli such as pH, photoirradiation, cations, anions, neutral species have been discussed. Advances and scope of supramolecular gels in various applications have also been mentioned in detail with respective examples. Utilities of supramolecular gels in synthesis of nanostructures, in biology and medicine, enzyme recognition, catalysis etc are discussed. (Scheme 2). Chapter 2: Charge transfer triggered organogels of bis(bile acid)anthracene conjugates and 2,4.7-trinitrofluorenone. In this chapter the study involves the synthesis of a special class of anthracene based steroidal derivatives. The appending of two amphiphilic bile acid units imparts a unique hydrophobic/ hydrophilic balance on the chromophore. The 2,3-didecyloxyanthracene (DDOA) was reported to be a gelator of various organic solvents but none of the three bile acid derivatives of anthracene synthesized was a gelator on its own. It was also observed that dialkoxy (propyl, heptyl, decyl) derivatives of anthracene formed strong charge-transfer gels in the presence of 2,4,7-trinitrofluorenone (TNF). The addition of electron deficient TNF to the steroidal derivatives of anthracene resulted in the gelation of some specific organic solvents. The driving force behind the gel formation resulted from the charge-transfer (CT) interaction between the electron rich anthracene and electron deficient fluorenone. Figure 1. Chemical structures of 2,3-bis(bile acid)anthracenes and TNF (centre), a scanning electronic microscopy image of xerogels prepared from bis(deoxycholyl)anthracene and TNF (left) and a photograph of the gel of bis(deoxycholyl)anthracene and TNF in n-octanol. Thermochromic property (during sol to gel phase transition), absorption and variable temperature fluorescence measurements supported CT interaction. Thermal stability studies and dynamic rheology experiments confirmed that CT gels were thermally most stable and mechanically stronger with equi-molar amounts of the two components. Stiffness values obtained from rheological experiments also suggested that the gels were viscoelastic solids. Chapter 3(A): Tb(III) sensitization in an organogel matrix: Selective luminescence quenching by an aromatic nitro derivative In this chapter the discovery of metallo organogel formation by mixing methanolic solutions of Tb(OAc)3 and sodium deoxycholate (NaDCh) has been explored. Sensitization of Tb3+ was observed by doping micromolar quantities of 2,3-dihydroxynaphthalene (DHN). Mechanical properties of Tb3+-DCh gels were investigated by rheology at three different ratios of Tb3+ and DCh. It was observed that increasing in the Tb3+ to DCh ratio increased the mechanical property of the gels. Time delayed emission spectra were recorded with increasing concentration of DHN and luminescence increase was noticed in a linear fashion. Importance of gel matrix was demonstrated by measuring the Tb3+ luminescence at fixed concentration (5 mM) with/without DHN in the solution and gel media. Figure 2:: Schematic representation of Tb3+ sensitization by DHN. Photograph (right)) of the Tb3++-DCh (5/15 mM) gels with (a) 50 µM DHHN (b) No DHHN under UVV (365 nm). Sensitization by an electron rich chromophore created interest in us to dope relatively electron deficient compounds into the gel matrix for possible quenching off Tb3+-luminescence. Among the electron deficient analytes screened included 1,5-difluro-2,4-diinitrobenzenne (DFDNB)), 2,4 dinitrophenol (DNPPh), p-nitrobenzaldehydde (p-NB), 2,4,6-trinitrootoluene (TTNT) and 22,4,7¬trinitrofluuorenone (TTNF). Microscopy studies such as AFM, TEMM and SEMM revealed highly entangled fibrous network in the morphology of Tb3+--DCh xerogel. Solid state luminescence experiments suggested that sensiitization was observed in the xerogels and extent of sensitization was comparable to that of the gel state. Xerogel soaking studies inferred the strong adherence of the DHNN to the gel fibres. Chapter 3(B): Anion dependent structural, morphological and mechanical features of Ln(III)-Cholate gels In this chapter the counter anion influence on various aspects of hydrogels has been discussed. It has been reported from our laboratory that mixing of aqueous solutions of sodium cholate (15 mM) and various lanthanide acetates (5 mM) followed by sonication resulted in either transparent or transluscent gels. Unsurprisingly we found that aqueous solutions of lanthanide nitrates and lanthanide chlorides also formed hydrogels upon mixing with sodium cholate (Figure 33). Dried films of Tb3++-cholate and Eu3+-cholate gels prepared from their respective nitrate salts displayed birefringent structures under polarizing optical microscopy (POM). But no significant textures of any type were observed in the case of gels prepared from either chloride or acetate salts. Figure 3:: Photographs of the hydrogels prepared by mixing of aqueous solutions of various salts Tb33+ and Eu3+ with sodium cholate solutions. Scanning electron microscopic images exhibited fibrous structures for all the xerogels in the morphology. Atomic force microscopy and transmission electron microscopy measurements revealed helical morphology for xerogels prepared from nitrate salts where as flat tape-like cross linkage was observed for chloride or acetate based xerogels. Anion effect on mechanical properties was significant in the sense that gels prepared from acetate salts displayed highest mechanical strength followed by nitrate based gels which were stronger than that of chloride based gels. Titration of sodium cholate solution with various lanthanide salt solutions gave the direct evidence of thee pH variation as a function of the anions. Figure 4: TEM images of xerogels prepared from gels of nitrate salts of Tb3+ (left) and Eu3+ (right) Chapter 4: Design, synthesis a nd study of bile acid ‘click’ conjugates of perylene bisimides (PBIs) and naphthalene bisimides (NBIs) In this chapter the synthesis of novel bile acid derivatives of perylene and naphthalene bisimides is discussed. The ‘click’ chemistry procedure was used to link bile acid groups on to the chromophores. Azide derivatives of PBIs and NBIs were prepared inn 3 step methods which were coupled to propargyl esters of bile acids by following standard ‘click chemistry’ protocols to achieve the target molecules (Scheme 3). Scheme 3 The studies conducted mainly focused on Cholic acid (CA) conjugates of PBIs and NBIs. Steady state absorption and emission studies of CA conjugates were performed in 10% MeOH/DCM system. POM and fluorescence images showed red emissive aggregates in case of PBI films. TEM measurements revealed uniform aggregate sizes for both the films of PBI(CA)2 and NBI(CA)2. SEM and AFM (Fig 5) studies exhibited spherical aggregates of diameter around 100-200 nm for PBI(CA)2 films where as aggregates of diameter around 500-700 nm were observed for NBI(CA)2 films. Figure 5: AFM images and their corresponding height profiles of PBI films (left) and NBI films (right)

This Thesis describes the synthesis and characterisation of new alkaline earth- and rare earth-transition metal complexes. Experimental and computational studies were performed to investigate the structure and bonding in these complexes. Their reactivity was also studied. Chapter 1 introduces metal-metal bonded complexes and current alkaline earth- and rare earth-transition metal bonded complexes. Chapter 2 describes experimental and computational studies of new alkaline earth- and lanthanide-Fe complexes possessing the [CpFe(CO)2]- anion. Chapter 3 presents experimental studies of the reduction of Fe3(CO)12 with Ca. Chapter 4 describes experimental and computational studies of new alkaline earth- and lanthanide-Co complexes containing the [Co(CO)3(PR3)]- anion. Chapter 5 presents full experimental procedures and characterising data for the new complexes reported. Appendix describes the attempted synthesis of [Ca{CpRu(CO)2}2(THF)x]y and study by DFT of [CaRp2(THF)3]2 CD Appendix contains .cif files for all new crystallographically characterised complexes described.

Lanthanide-based nanoparticles are of interest for optical displays, catalysis, telecommunication, bio-imaging, magnetic resonance imaging, multimodal imaging, etc. These applications are possible partly because the preparation of lanthanide-based nanoparticles has made tremendous progress. Now, nanoparticles are routinely being made with a good control over size, crystal phase and even shape. Despite the achievements, little attention is given to the fundamental physical chemistry aspects, such as crystal structure, architecture, cation exchange, etc. The results of the study on the crystal structures of LnF3 nanoparticles show that the middle GdF3 and EuF3 nanoparticles have two crystal phases, which has then been tuned by doping with La3+ ions. However, the required doping level is very different from the bulk. While the results for the bulk are well explained by thermodynamic calculations, kinetics is actually responsible for the results of the undoped and doped GdF3 and EuF3 nanoparticles. The attempt to make LnF3 core-shell nanoparticles led to the finding of cation exchange, a phenomenon that upon exposure of LnF3 nanoparticles to an aqueous solution containing Ln3+ ions, the Ln3+ ions in the nanoparticles are replaced by the Ln3+ ions in the solution. The consequence of the cation exchange is that LnF3 core-shell nanoparticles are unlikely to form in aqueous media using a core-shell synthesis procedure. It has also been verified that nanoparticles synthesized using an alloy procedure do not always have an alloy structure. This means that the core-shell and alloy structure of nanoparticles in the literature may not be true. The investigation of the architecture of nanoparticles synthesized in aqueous media is extended to those synthesized in organic media. The dopant ion distribution in NaGdF4 nanoparticles has been examined. It has been found that they don’t have the generally assumed statistical dopant distribution. Instead, they have a gradient structure with one type of Ln3+ ions more concentrated towards the center and the other type more concentrated towards the surface of the nanoparticles. With the understanding of these physical insights, lanthanide-based core-shell nanoparticles are prepared using the cation exchange. These core-shell nanoparticles containing a photoluminscent core and a paramagnetic shell are promising candidates for multimodal imaging. / Graduate

Lanthanide elements display many remarkable and exciting properties which explain their widespread use in a number of very important biomedical tools like efficient MRI contrast agents or luminescent probes for highly sensitive assays of bioanalytes amongst other fields of application. In this context, the aim of the present work was to prepare and characterize lanthanide complexes of two ligands that feature a linear or a macrocyclic chelating unit compactly grafted onto a 1,10-phenanthroline derived moiety (phenDTPA and PhenHDO3A). The ditopic nature of the ligands allows the selective incorporation of a d6 metal ion and a lanthanide one in close proximity. The resulting rigid heterobimetallic supramolecular species show useful properties and constitute potential MRI contrast agents or new luminescent compounds depending on the type of the lanthanide and transition metal ions employed: for example, the selfassembly process of gadolinium(III) chelates around an iron(II) ion brings a remarkable increase of their relaxivity, a key parameter for use in MRI. On the other hand, association of a ruthenium and and a near infrared emitting 4f ion like ytterbium(III) gives mixed d-f structures able to harvest visible light and convert it into near infra-red signal. Visible light luminescent pH probes were also obtained with Eu3+ or Tb3+ phenHDO3A complexes.

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Dreiwertige Actinide (An(III)) und Lanthanide (Ln(III)) stellen im Falle ihrer Inkorporation eine ernste Gefahr für die Gesundheit des Menschen dar. An(III) sind künstlich erzeugte, stark radioaktive Elemente, die insbesondere bei der nuklearen Energiegewinnung in Kernkraftwerken entstehen. Durch Störfälle oder nicht fachgerechte Lagerung radioaktiven Abfalls können sie in die Umwelt und die Nahrungskette des Menschen gelangen. Ln(III) sind hingegen nicht radioaktive Elemente, die natürlicherweise vorkommen und für vielfältige Anwendungen in Technik und Medizin abgebaut werden. Folglich kann der Mensch sowohl mit An(III) als auch Ln(III) in Kontakt kommen bzw. sie inkorporieren. Es ist daher von enormer Wichtigkeit, das Verhalten dieser Elemente im menschlichen Körper aufzuklären. Während makroskopische Vorgänge wie Verteilung, Anreicherung und Ausscheidung bereits sehr gut untersucht sind, ist das Wissen hinsichtlich der chemischen Bindungsform (Speziation) von An(III) und Ln(III) in Körperflüssigkeiten noch sehr lückenhaft. In der vorliegenden Arbeit wurde daher erstmals die chemische Bindungsform von Cm(III) und Eu(III) in natürlichem menschlichem Urin (in vitro) spektroskopisch aufgeklärt und die gebildeten Komplexe identifiziert. Hierzu wurden auch grundlegende Untersuchungen zur Komplexierung von Cm(III) und Eu(III) in synthetischem Modellurin sowie mit den urinrelevanten organischen Modellliganden Harnstoff, Alanin, Phenylalanin, Threonin und Citrat durchgeführt und die noch unbekannten Komplexbildungskonstanten bestimmt. Abschließend wurden alle experimentellen Ergebnisse mit Literaturdaten und Vorherberechnungen mittels thermodynamischer Modellierung verglichen. Auf Grund der hervorragenden Lumineszenzeigenschaften von Cm(III) und Eu(III) konnte insbesondere auch die Eignung der zeitaufgelösten laserinduzierten Fluoreszenzspektroskopie (TRLFS) als Methode zur Untersuchung dieser Metallionen in unbehandelten, komplexen biologischen Flüssigkeiten demonstriert werden. Die Ergebnisse dieser Arbeit liefern damit neue Erkenntnisse zu den biochemischen Reaktionen von An(III) und Ln(III) in Körperflüssigkeiten auf molekularer Ebene und tragen zu einem besseren Verständnis der bekannten, makroskopischen Effekte dieser Elemente bei. Darüber hinaus sind sie die Grundlage weiterführender in-vivo-Untersuchungen. / In case of incorporation, trivalent actinides (An(III)) and lanthanides (Ln(III)) pose a serious health risk to humans. An(III) are artificial, highly radioactive elements which are mainly produced during the nuclear fuel cycle in nuclear power plants. Via hazardous accidents or nonprofessional storage of radioactive waste, they can be released in the environment and enter the human food chain. In contrast, Ln(III) are nonradioactive, naturally occurring elements with multiple applications in technique and medicine. Consequently it is possible that humans get in contact and incorporate both, An(III) and Ln(III). Therefore, it is of particular importance to elucidate the behaviour of these elements in the human body. While macroscopic processes such as distribution, accumulation and excretion are studied quite well, knowledge about the chemical binding form (speciation) of An(III) and Ln(III) in various body fluids is still sparse. In the present work, for the first time, the speciation of Cm(III) and Eu(III) in natural human urine (in vitro) has been investigated spectroscopically and the formed complex identified. For this purpose, also basic investigations on the complex formation of Cm(III) and Eu(III) in synthetic model urine as well as with the urinary relevant, organic model ligands urea, alanine, phenylalanine, threonine and citrate have been performed and the previously unknown complex stability constants determined. Finally, all experimental results were compared to literature data and predictions calculated by thermodynamic modelling. Since both, Cm(III) and Eu(III), exhibit unique luminescence properties, particularly the suitability of time-resolved laser-induced fluorescence spectroscopy (TRLFS) could be demonstrated as a method to investigate these metal ions in untreated, complex biofluids. The results of this work provide new scientific findings on the biochemical reactions of An(III) and Ln(III) in human body fluids on a molecular scale and contribute to a better understanding of the known macroscopic effects of these elements. Furthermore, they are the basis of subsequent in vivo investigations.

La fluorescence en temps résolu est une méthode d'analyse spectrophotométrique avancée permettant la sélection des photons émis par luminescence sur un critère temporel. Il est ainsi possible, et cela même dans des milieux complexes et pollués issu de l'industrie, de faire émerger sélectivement le signal d'espèces luminescentes présentant des durées de vie de luminescence relativement grandes.Ce type d'analyse spectrale est particulièrement adapté à la détection de trace d'éléments lanthanides. Chacun des éléments de la série présente en effet des propriétés luminescentes uniques bien que largement fonction de la nature des ligands qui les entourent. Les travaux de thèse présentés dans ce manuscrit utilisent avantageusement la constatation précédente. Deux technologies ont étés mise sur pied et/ou optimisées pour permettre un transfert vers des domaines industriels aux cahiers des charges bien définis.Ainsi dans le domaine de la lutte anti-contrefaçon l'ajout de marqueurs luminescents à temps résolu à base de lanthanide rend possible la surveillance de l'origine et du devenir de divers produits industriels.Dans le domaine pétrolier l'analyse des effluents à l'aide de sondes luminescentes à base de lanthanide permet de quantifier le taux résiduel de plusieurs classes d'additifs chimiques et permet d'optimiser la sécurité, la rentabilité et l'impact écologique du processus d'extraction.Dernièrement un prototype de spectrofluorimètre résolu en temps adapté à un usage industriel a été mis au point pour permettre un transfert technologique du laboratoire vers le milieu industriel / Time-resolved fluorescence is an advanced spectrophotometric analysis method which allows the selection of emitted luminescent photons on a time-based parameters. It is possible to extract the signal of long-lived luminescent species even in complex and polluted matrix from the industry. This type of analysis is especially fitted for the detection of lanthanide ions. During this thesis two technologies based on time-resolved analysis were designed to answer specific industrial problematics. The first one yields the residual concentration of chemical additives used during oil and gas extraction. The second one aims at protecting crude oils and refined fuels from counterfeiting. They both rely on the use of lanthanide complex and the measurement of their luminescent properties. A prototype of time-resolved spectrofluorimeter was also built to transfer the technologies from the laboratory to the industrial world