Les nouvelles exigences du diagnostic clinique et de la thérapeutique, particulièrement en termes d’examens au chevet du patient et en médecine de précision, ont conduit à une demande croissante d’analyses à la fois multiplexées et présentant un rendement important, et ce d’un grand nombre de biomolécules au sein d’un échantillon unique. La thèse se concentre sur le développement de biosenseurs multiplexés basés sur le transfert d’énergie par résonance de type Förster résolu en temps de complexes de lanthanide vers des colorants organiques ou des boîtes quantiques. Je présente plusieurs techniques novatrices permettant la détection simultanée et multiplexée de protéines biomarqueurs du cancer (récepteur du facteur de croissance épidermique) ou de microARNs (hsa-miR-20a-5p, hsa-miR-20b-5p et hsa-miR-21-5p) avec de très faibles limites de détection. J’ai utilisé différentes stratégies afin d’obtenir des détections multiplexées telles la détection multiplexée spectrale basée sur les différents spectres d’émission de différents luminophores, et la détection multiplexée temporelle basée sur les durées de vie distinctes des états excités des luminophores. Ces travaux ne sont pas seulement une recherche appliquée qui peut être utilisée en diagnostic clinique, mais constituent également une recherche fondamentale sur le FRET résolu en temps qui ouvre de nouvelles perspectives de détection et augmente considérablement le nombre de biomarqueurs pouvant être détectés. / The new mission of clinical diagnostics and therapeutics, especially in point-of-care testing and precision medicine, has led to an increasing demand for multiplex and high throughput analyses of large numbers of biomolecules within a single sample. The thesis focuses on developing multiplexed biosensors based on time-resolved Förster resonance energy transfer from lanthanide complexes to organic dyes or quantum dots. I present several new techniques to simultaneously and multiplexed detect cancer related protein biomarkers (human epidermal growth factor receptor) or microRNAs (hsa- miR-20a-5p, hsa-miR-20b-5p and hsa-miR-21-5p) with very low limits of detections. I have used different strategies to achieve multiplexed detections such as spectral multiplexed detection based on different emission spectra of different luminophores, and temporal multiplexed detection based on distinguishable excited-state lifetimes of luminophores. The work is not only an applied research that can be used in clinical diagnostics but also a fundamental research of time-resolved FRET, which opens a new dimension of detection and greatly increases the number of biomarkers that can be detected.

In 2012, The Institute of Resource Ecology at the Helmholtz-Zentrum Dresden Rossendorf organized the first international workshop of Advanced Techniques in Actinide Spectroscopy (ATAS). A very positive feedback and the wish for a continuation of the workshop were communicated from several participants to the scientific committee during the workshop and beyond. Today, the ATAS workshop has been obviously established as an international forum for the exchange of progress and new experiences on advanced spectroscopic techniques for international actinide and lanthanide research. In comparison to already established workshops and conferences on the field of radioecology, one main focus of ATAS is to generate synergistic effects and to improve the scientific discussion between spectroscopic experimentalists and theoreticians. The exchange of ideas in particular between experimental and theoretical applications in spectroscopy and the presentation of new analytical techniques are of special interest for many research institutions working on the improvement of transport models of toxic elements in the environment and the food chain as well as on reprocessing technologies of nuclear and non-nuclear waste. Spectroscopic studies in combination with theoretical modelling comprise the exploration of molecular mechanisms of complexation processes in aqueous or organic phases and of sorption reactions of the contaminants on mineral surfaces to obtain better process understanding on a molecular level. As a consequence, predictions of contaminant’s migration behaviour will become more reliable and precise. This can improve the monitoring and removal of hazardous elements from the environment and hence, will assist strategies for remediation technologies and risk assessment. Particular emphasis is placed on the results of the first inter-laboratory Round-Robin test on actinide spectroscopy (RRT). The main goal of RRT is the comprehensive molecular analysis of the actinide complex system U(VI)/acetate in aqueous solution independently investigated by different spectroscopic and quantum chemical methods applied by leading laboratories in geochemical research. Conformities as well as sources of discrepancies between the results of the different methods are to be evaluated, illuminating the potentials and limitations of cou-pling different spectroscopic and theoretical ap-proaches as tools for the comprehensive study of actinide molecule complexes. The test is understood to stimulate scientific discussions, but not as a competitive exercise between the labs of the community. Hopefully, the second ATAS workshop will continue to bundle and strengthen respective research activities and ideally act as a nucleus for an international network, closely collaborating with international partners. I am confident that the workshop will deliver many exciting ideas, promote scientific discussions, stimulate new developments and collaborations and in such a way be prosperous. This workshop would not take place without the kind support of the HZDR administration which is gratefully acknowledged. Finally, the or-ganizers cordially thank all public and private sponsors for generous funding which makes this meeting come true for scientists working on the heavy metal research field.

Chapter 1: Introduction to the luminescent properties of lanthanides Luminescence properties of trivalent lanthanides have been explored extensively over the past few decades owing to their unique properties. Lanthanides emission is known to be due to intra-configurational f-f transitions. Because the partially filled 4f shell is well shielded from its 26 environment by the closed 5sand 5pshells, the ligands in the first and second coordination sphere perturb the electronic configurations of the trivalent lanthanide ions only to a very limited extent. This leads to interesting properties such as long lifetimes, sharp line-like emissions etc. which in turn make lanthanides very attractive choice for commercial optical applications. Despite this, the scope of applications remained limited because of the low molar extinction coefficient values of the forbidden lanthanide f-f transitions. However, this problem has been successfully addressed by complexing the lanthanide ion with suitable ligands which can sensitize it resulting in a significant increase in the emission intensity (so called “antenna effect”). The strategy worked very well and resulted in widespread applications of lanthanides form biology to optoelectronics. This chapter discusses elementary ideas regarding the mechanism of sensitization and relevant examples that traces various applications of such lanthanide complexes from the current literature. Chapter 2: A self-assembled Europium Cholate hydrogel: a novel approach towards lanthanide sensitization Luminescent lanthanides can be of great value in a number of possible applications but their scope is limited by their intrinsic low molar absorptivities. Though this problem can be circumvented by complexing the lanthanide ion with suitable chelating ligands to improve the luminescence properties drastically, the design of such systems often involves meticulous planning and laborious synthetic steps to obtain a ligand suitable for the job. It is therefore desirable to have a simpler version of a sensitizing system that does not require the complexities of a chelating ligand but can sensitize trivalent lanthanides with comparable efficiency. It was observed in our group that divalent metal ions (Ni2+, Zn2+, Cu2+, Coetc.) form hydrogels on addition of sodium cholate. We extended to obtain hydrogels of trivalent lanthanides. Furthermore, when the gel was doped with pyrene, a ten-fold increase in the intensity of Eu(III) emission was observed (Fig 2). Thus we established a unique way to sensitize lanthanides in a hydrogel media by non-coordinating chromophores. The approach was completely modular in nature and avoids any laborious synthesis. We also tried other derivatives of pyrene as sensitizers and found that 1-pyreneboronic acid also caused similar sensitization of Eu(III). Fig 2. (a) Schematic representation of the sensitization process (the arrangement of molecules in the gel fiber is arbitrary). Eu-cholate (5 mM/15 mM) gel (a) normal light and (b) 354 nm UV excitation in the presence of 6 μM pyrene Further studies revealed, that 2,3-dihydroxynapthalene (DHN) can sensitize Tb(III) in a similar hydrogel. We also demonstrated Tb(III) to Eu(III) energy transfer process occurring in the gel when doped with DHN. This allowed us to achieve a hydrogel system with tunable luminescence properties (by varying relative ratios of Tb(III) and Eu(III) ). When the effect of divalent metal ions on such energy transfer processes were explored, it was observed that the luminescence from the composite gel of Tb(III)/ Eu(III) is tunable by Zn(II) and through proper manipulation of concentrations one can obtain white light emitting gel (Fig 3). Fig 3. Effect of Zn(II) (from left to right 0 mM, 2.8 mM, 11.3 mM) on Tb3+ (4.5 mM)/Eu3+ (0.11mM)/ sodium cholate (13.6 mM) gels. b) Tb/Eu/Zn-cholate gel (Tb3+ (4.4 mM), Eu3+ (0.11 mM), Zn2+ (7.4 mM), NaC (13.6 mM, DHN 0.2 mM) under 365 nm UV lamp (c) CIE 1931 diagram depicting the luminescence as white (black spot). Chapter 3. A “Pro-Sensitizer” based Sensing of Enzymes using Tb(III) Luminescence in a Hydrogel matrix This chapter descirbes design and realisation of a sensor system based on Tb(III) luminescnece for the detection of enzymes. The idea involved synthesizing a covalently modified DHN molecule by attaching appropriate enzyme cleavable units. We coined the term “pro-sensitizer”to describe the modified molecule which would not sensitize Tb(III) in the gel matrix but when proper enzymes are applied the free form of DHN would be released triggering a luminescence response from Tb(III). This would enable us to monitor the acitivities of the particular enzyme by examining the luminescence intensity enhancement with time (Fig 4) Fig 4. A “pro-sensitizer” based approach to detect different types of enzymes in a hydrogel matrix through Tb(III) luminescence. We applied the idea to develop a novel luminogenic gel probe for inexpensive and rapid detection of three different hydrolases, lipase, β–glucosidase and α-chymotrypsin. The corresponding “pro-sensitizer”for each enzyme were synthesized (Fig 5).The sensing technique depends on the gel matrix to provide the nessesary platform for lanthanide sensitization. Thereofore, it enjoys an edge over the contemporary techniques that typically involve specially designed and synthesized multidentate chelating ligands for this purpose. We also determined important kinetic parameters of all the enzymes, thus enabling us to have a better insight into the activity of the enzymes in the hydrogel matrix. Fig 4. Pro-sensitizers molecules for (1) lipase, (2) β-glucosidase and (3)α-chymotrypsin Chapter 4. A novel approach towards templated synthesis of lanthanide trifluoride nanoparticles Nanomaterials with excellent optical properties have been of special interest. Lanthanide derived nanoparticles, owing to their unique physical properties, provide an excellent choice for applications such as biolabels, lasers, optical amplifiers, and optical-display phosphors. Several types of lanthanide nanoparticles or nanocrystals are reported in the literature such as Nd2O3, Eu2O3, Gd2O3, Tb2O3, and Y2O3. Among them lanthanide fluoride nanoparticles have emerged as the best choice because of their low phonon energy, and thus minimum quenching of emissive Lnions thereby allowing maximum efficiency for several optical applications. In previous literature precedence, LnF3 nanoparticles were typically synthesized following conventional approaches which necessitate use of high temperatures, high pressures (hydrothermal techniques) and capping ligands. In this chapter, we demonstrated a simpler synthesis of LnF3 nanoparticles at ambient temperatures without the requirement of added capping agents. The room temperature synthesis of LnF3 was unprecedented and was achieved simply by diffusing NaF solution through the hydrogels of corresponding Ln-cholate gels. The nanoparticles were characterized by transmission electron microscopy (TEM) and by powder XRD analysis which established the presence of very small (3-4 nm) nanoparticles mono-dispersed uniformly over the the gel matrix (Fig 6). The LnF3 containing xerogels of Tb(III) and Eu(III) cholate gels were also shown to be highly emissive. Fig 6. HRTEM images of a) TbF3, b) GdF3, c) NdF3 and d) DyF3 in their corresponding gel media.

The advantage of one-bead-one-compound combinatorial libraries is that hundreds of thousands to millions of compounds can be rapidly synthesized and screened simultaneously. The beads supporting the compounds of interest are then isolated and analyzed to decipher the structure of the desired compound. Many methods are currently used to allow deconvolution of the compound on the individual beads. Herein is described a novel method to encode TentaGel beads using absorption of different ratios of lanthanide ions. The encoding process is completed in parallel with the synthesis of the library of compounds. Once the desired beads are identified, the lanthanide ions can be released from the bead and analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS).

A presente dissertação descreve a preparação e caracterização dos compostos de adição entre metanossulfonatos de lantanídeos e ítrio e a 3-picolina-N-óxido (3-picNO). Foram preparados, a partir do metanossulfonato de lantanídeo hidratado e a 3-picNO, utilizando-se como \"meio de interação\" acetona, ortoformiato de trietila ou 2,2-dimetoxipropano. Os compostos de adição obtidos foram caracterizados por análise elementar, medidas de intervalos de fusão, condutância eletrolítica em solução metanólica, difratogramas de raios-X, espectros de absorção na região do infravermelho, espectros eletrônicos do composto de neodímio e espectros de fluorescência do composto de európio. As análises evidenciaram que os compostos mantêm a coloração do respectivo íon lantanídeo hidratado, possuem aspec to cristalino e, na série, uma higroscopicidade crescente. Esta, aliada à dificuldade de preparação e aos intervalos de fusão aparentes, que diminuem com o aumento do número atômico do lantanídeo, sugeriram um relacionamento com o raio iônico médio do ion Ln3+ e uma diminuição na estabilidade dos complexos com a contração lantanídica devida ao enfraquecimento da interação metal-ligante. Finalmente, os resultados analíticos (percentagem de Ln) obtidos por titulação complexométrica com EDTA e a percentagem de carbono, hidrogênio e nitrogênio, determinados por microanálise, permitiram estabelecer a fórmula geral: Ln(MS)3.2(3-picNO) (Ln = La-Yb e Y). As medidas de condutância em metanol indicaram um comportamento de não eletrólito, sugerindo a coordenação do íon MS- ao íon Ln3+. Os difratogramas de raios-X determinaram que os compostos de adição pertencem a urna única série isomorfa. Quanto aos espectros de absorção na região do infravermelho não se conseguem distinguir inequivocamente as bandas relativas ao estiramento NO (vNO) das bandas do estiramento assimétrico (v asso), mas ficam claro que houve um deslocamento da frequência VNO . Observaram-se pequenos deslocamentos positivos dos modos δNO e γC-H em relação ao ligante livre e também verificaram-se os desdobramentos para v asSO e vC-S. Não se observou as bandas características da molécula de água. Isto permitiu chegar às seguintes conclusões: a) a coordenação da 3-picNO ao íon metálico é feita através do oxigênio do grupo NO; b) a coordenação do ânion MS- evidenciada pelos dados de condutância é confirmada; c) as moléculas de água de hidratação do sal são completamente substituídas pelas moléculas de 3-picNO nos compostos de adição; d) a coordenação do MS- que no sal hidratado se admitia tridentada, possivelmente foi modificada para bidentada nos compostos em questão; e) os compostos de adição podem ser agrupados numa mesma série espectral. Os espectros eletrônicos do composto de neodímio no estado sólido, à temperatura ambiente, e do nitrogênio líquido permitiram determinar os parâmetros nefelauxêticos, o fator de covalência e o parâmetro de Sinha, os quais mostraram que a interação metal-ligante é essencialmente eletrostática, com os orbitais 4f participando muito pouco da ligação. O espectro registrado a baixa temperatura evidenciou, pelo numero de bandas, que os íons Nd3+ estão envolvidos em simetria não cúbica, fato que é confirmado pelo espectro de emissão do composto de európio, A semelhança entre os espectros de absorcão do composto de adição com aqueles dos sais anidros e hidratados em solucão metanólica evidenciam a existência das mesmas espécies nesta solução, Os parâmetros β-, δ, bl/2 e P indicam que os compostos são semelhantes àqueles obtidos com o ligante 2-picNO, Os espectros de fluorescência do composto de európio no estado sólido à temperatura ambiente e do N2 líquido apresentam urna banda relativa à transição 5D0→7F0, três bandas das transições 5D0→7Fl e quatro bandas curacterísticas das transições 5D0→7F2. Estes dados permitem sugerir que o íon de Eu3+ está envolvido numa simetria C3v proveniente, provavelmente, de uma distorção da simetria D3h. Foi sugerido que os ompostos Ln(MS)3.2(3-picNO) apresentam número de coordenação oito e estrutura de prisma trigonal biencapuzado, onde as moléculas de 3-picNO atuam corno capuz através das bases triangulares do prisma. Verificamos, ainda, que, embora se realize a síntese dos compostos de adição com a relação sal-ligante 1:5, a fórmula geral Ln(MS)3.2(3-picNO) se mantém, enquanto a 2-picNO forma compostos de adição com duas estequiometrias distintas Ln (MS)3.2 (2picNO) e Ln(MS)3.4(2-picNO). Isto demonstra que a 2-picNO atua como um ligante mais forte que a 3-picNO, ou seja, apesar dos efeitos estéricos mais pronunciados, o grupo metil, quando se encontra na posição 2_ não influencia na coordenação, Já o oposto se observa quando o ânion apresenta propriedades não coordenantes. / This dissertation describes the preparation and characterization of the additions compounds between yttrium and lanthanide methanesulfonate and 3-picoline-N-oxide (3-picNO). The compounds were prepared from the hydrated lanthanide methanesulfonate and 3-picNO in acetone, triethylorthoformate or 2,2-dimethoxypropane as \"interaction medium\". The adducts were characterized by elemental analysis, melting ranges, electrolitic conductance in methanol, X-ray powder patterns, IR spectra, electronic spectra of neodymium and europium compounds. The analytical results (% Ln, C, H and) indicate the general formula: Ln(MS)3.2(3-picNO) (Ln = La-Yb e Y. The complex presents the same lanthanide (III) colours, are crystalline, the hygroscopicity increases in the series. The apparent melting ranges decreases with ionic Ln3+ radii . The stability of the complexes decreases, due to the lanthanidic contriction that make more unstable the Ln:L interaction. Conductance measurements, in methanol, indicate non-electrolyte behavior. According to X-ray powder pattern, only one isomorphous series was detected. The bands attributed to vNO are not inequivocally distinguished from vasSO in the IR spectra, but certainly there is a shift of the vNO to lower frequencies, in relation to the free 3-picNO. Positive shifts of δNO and γCH and spplittings of vasSO and vC-S were also observed, which permit the following conclusion: a) the 3-picNO is bonded through the oxygen; b) the MS ion is coordenated to the central ion (confirming the conductance data); c) water molecules from the salt were completed substituted by the 3-picNO; d) MS ions probably act as bidentate; e) the compounds present only one spectral series. From the electronic absorption spectra of the neodymium compounds the nefelauxetic parameter, covalent factor and Sinha\'s parameter were calculated and suggest a essentially electrostatic metal-ligand bond. The number of bands, at 77 K indicate that the Ln ion is not involved in a cubic site. The spectroscopic data show that they are similar to that of the 2-picNO compound. Fluorescence spectra of the Eu complex present peaks due to 5D0→7F0 (one), 5D0→7Fl (three) and 5D0→7F2, (four) transitions and were interpreted in terms of C3v symmetry, due to a distortion of the D3h. The geometry of a bicapped trigonal prism with two 3-picNO acting as capps of the triangular bases is proposed. The same stoichiometry is obtained when 1:5 or 1:3 relation between Ln:L was used. In contrast with the 2-picNO where the compositions Ln(MS)3.2(2-picNO) and Ln(MS)3.4(2-picNO) were obtained, this means that 2-picNO is stronger than 3-picNO ligand, despite the fact the 2-picNO show pronounced steric hyndrance.

O objetivo deste trabalho é dar continuidade e ampliar os estudos quanto a preparação e caracterização dos compostos de adição obtidos pela reação entre metanossulfonatos de lantanídeos e aminóxidos aromáticos como ligantes, mais especialmente a piridina-N-óxido (pyO) e as metil piridinas-N-óxidos monossubstituidas, ou seja, as picolinas-N-óxidos (2-picNO, 3-picNO e 4-picNO); e estabelecer um estudo comparativo. Anteriormente, foram sintetizados e caracterizados os compostos de adição: Ln(MS)3.2(2-picNO) (Ln = Ce-Sm), Ln(MS)3. 4(2 -picNO) (Ln = La-Lu,Y) e Ln(MS)3.2(3-picNO) (Ln = La-Lu-Y). Nesta tese, preparou-se as outras duas séries de compostos contendo como ligante 4-picNO e pyO. Similarmente aos anteriores, utilizou-se nas sínteses, como \"meio de interação\" acetona, orformiato de trietila ou 2,2-dimetoxipropano, partindo-se de soLuções metanólicas do sal e do ligante. A caracterização foi feita via análise elementar, medidas de intervalos de fusão, condutância eletrolítica em solução metanólica, difratogramas de raios-X, espectros de absorção na região do infravermelho, espectros eletrônicos dos compostos de Nd e espectros de emissão dos compostos de Eu. Os compostos obtidos são sólidos, de aspecto cristalino e pulverulento, de leve odor, característico do aminóxido correspondente, de coloração semelhante à dos cátions hidratados e uma dificuldade de preparação e higroscopicidade crescente através da série. Estas, aliadas aos intervalos de decomposição térmica, que decrescem com o aumento do número atômico do lantanídeo, sugeriram um relacionamento com o raio médio do íon Ln3+ e uma diminuição na estabilidade dos complexos com a contração lantanídica devido ao enfraquecimento da ligação metal-ligante. A comparação entre os compostos de adição mostrou que Ln(MS)3.2(4-picNO) e Ln(MS)3.2pyO foram obtidos com maiores dificuldades do que aqueles sintetizados e caracterizados anteriormente, em que se utilizou o ligante 3-picNO. Em ambas as séries, não foram isolados na forma sólida os compostos de Yb e Lu. Os resultados analíticos (%Ln, %C, %H e %N), foram consistentes com a fórmula geral Ln(MS)3.2L, semelhante aos compostos obtidos com a 3-picNO, porém diferentes daqueles formados com a 2-picNO que apresentaram duas estequiometrias distintas. Este resultado evidenciou que a posição grupo metila no anel aromático influencia na capacidade coordenante do aminóxido aromático. As medidas de condutância em metanol indicaram um comportamento de não eletrólito, sugeri ndo a coordenação do íon MS- ao Ln3+. Os difratogramas de raios-X indicaram que em cada série de compostos ocorre o fenômeno de isomorfismo, que parece ser uma característica dos compostos de fórmula geral Ln(MS)3.2L (L = 2-picNO, 3-picNO, 4-picNO e pyO). Nos espectros de absorção na região do IV observam-se deslocamentos das bandas relativas ao estiramento NO (VNO ) para frequências menores em relação ao ligante livre. Porém não foi possível avaliar a extensão do deslocamento uma vez que o ânion MS- apresenta bandas de absorção na mesma região. Observam-se deslocamentos positivos dos modos &#947;C-H em relação ao ligante livre, característicos do decréscimo da densidade eletrônica no anel devido a coordenação do aminóxido aromático através do oxigênio. Verificou-se desdobramentos para as bandas vasSO e &#948;S03 característicos do abaixamento da simetria do ânion e indicativos da alteração no seu modo de coordenação; enquanto no sal hidratado admitiu-se o ânion atuando como tridentado, nos compostos de adição foi sugerido que o grupo CH3S03 atue como bidentado. Os espectros eletrônicos dos compostos de neodímio no estado sólido, à temperatura ambiente, permitiram determinar os parâmetros espectroscópicos: -&#946;, b1/2 e &#948;, os quais indicaram a interação metal-ligante como essencialmente eletrostática, com os orbitais 4f participando muito pouco da ligação. Os espectros registrados à baixa temperatura evidenciaram que os íons Nd3+ estão envolvidos em simetria não cúbica. A força do oscilador, P, foi determinada a partir dos espectros dos compostos de Nd em solução metanólica e analogamente aos compostos formados com 3-picNO e 2-picNO o valor é praticamente o dobro em relação aqueles determinados para os metanossulfonatos de lantanídeos anidros e hidratados. Os espectros de emissão dos compostos de európio no estado sólido à temperatura ambiente e do N2 líquido foram registrados na região do visível. A partir das linhas de emissão características das transições 7F0,1,2 &#8592; 5D0 sugeriu-se que tanto no composto Eu(MS)3.2(4-picNO) como no Eu(MS)3.2pyO o íon Eu3+ está envolvido numa simetria próxima da C3V; fato semelhante foi apontado para o composto Eu(MS)3.2(3-picNO). A partir desta sugestão e com os dados obtidos destes espectros foram calculados os parâmetros do campo cristalino B20, B40 e B40, os quais possibilitaram a obtenção do parâmetro escalar de força do campo cristalino (Nv ). / The main goal of this thesis is to further develop the studies on the preparation and characterization of addition compounds obtained from the reaction of lanthanide methanesulphonates and aromatic aminoxides as ligands, soecifically pyridine-N-oxide (pyO) and monosubstituted methyl pyridine-N-oxides as the picoline-N-oxides (2-picNO, 3-picNO and 4-picNO) in order to make a comparative study. Addition compounds of the series: Ln(MS)3.2(2-picNO) (Ln = Ce-Sm); Ln(MS) 3.4C2-picNO) (Ln = La-Lu, Y) and Ln(MS) 3.2(3-picNO) (Ln = La-Lu, Y) had already been synthetized and characterized. We now prepared two series of compounds using 4-picNO and pyO as ligands. As in earlier cases we employed acetone, triethyl-orthoformiate or 2,2-dimethoxypropane as \"interaction medium\" when using methanolic salt and ligand solutions. Characterization was made via elementary analysis, melting point intervals, electrolytic conductance in methanol, X-ray difractograms, absorption spectra in the infrared region, electronic spectra of the Nd3+ and emission spectra of Eu3+</sup< compounds. The compounds are solid, crystalline and powdered with a light scent characteristic of the corresponding aminoxide. The colours are similar to those of hydrated cations. The difficulties on preparation and tendency to be hygroscopic increase along the series. These difficulties as well as the thermal decomposition intervals (decreasing with the lanthanide\'s atomic number) led to the suggestion of a relationship with the mean ionic radius of the Ln3+ ion and the decrease in stability being due to the weakening of the metal-ligand bond. As compared to earlier results it was noted that compounds with 4-picNO and pyO are more difficult to synthetize since Yb and Lu compounds could not be isolated. The analytical results (%Ln, %C, %H and %N) are consistent with a general formula Ln(MS)3.2L as was also the case with 3-picNO but different from 2-picNO compounds which showed two distinct stoichiometries. This result is a further evidence that the methyl group position on the aromatic ring definitively has influence on the coordinating capacity of the aromatic aminoxide. Conductance measurements in methanol indicate a non-electrolyte behaviour, suggesting coordination of the MS- íon to Ln3+. The X-ray diffraction patterns are indicative of isomorphism in each serie, which seems also to be characteristic of the compounds of general formula Ln(MS)3.2L (L = 2picNO, 3-picNO 4-picNO and pyO). The IR absorptíon spectra permit the observation that NO stretching ( VNO) shifts to Lower frequencies were observed as compared to the free ligand. It was imoossible to evaluate the extension of the shift due to the fact that MS- anion presents absorotion bands at the same region. Positive shifts of the &#947;C-H modes are observed, characteristic of electronic density decrease on the ring due to the coordination of the aromatic aminoxide through the oxygen. The vasSO and, &#948;S03 bands shifts are characteristic of anion lowering symmetry and indicative of an alteration in the coordination mode; whereas in the hydrated salt the anion is admitted as tridentade, we suggest a bidentade behaviour for the addition compounds. The neodymiun compounds electronic spectra in the solid state at room temperature permited us the determination of the -&#946;, b1/2 and &#948; spectroscopic parameters which are indicative of an essentially eletrostatic metal-ligand interaction with a very low participation of 4f orbitals. Spectra registered at low temperature present evidences of Nd3+ ions involvement in a non cubic symmetry. The oscillator strength, P, was determined from compounds in methanolic solution and, in similar way 3-picNO and 2-picNO compounds, the value is practically twice the value of those determined for the methanesulphonates of anhydrous or hydrated lanthanides. The emission spectra of the europium compounds were obtained in the visible region. From the characteristic emission lines of the 7Fo,1,2 &#8592; 5D0 transitions we suggest that both in the Eu(MS)3.2(4-picNO) and in the Eu(MS)3.2pyO compounds the Eu3+ ion is involved in a near C3v symmetry; a similar situation was found for the Eu(MS)3.2(3-picNO) compound. From this suggestion and from obtained from the spectra the B20, B40 and B43 crystal field parameters were calculated and related to the scalar crystal field parameter Nv.

lantanídeos, visando a determinação da simetria de coordenação ao redor dos íons e sua comparação com prévias previsões espectroscópicas. As medidas de difração foram realizadas com um difratômetro de quatro círculos de geometria Kappa. Os dados cristalinos relevantes são: [Eu (TMU)6] (AsF6)3, TMU = C5H12N2O. Fórmula química: EuC30H72N12O6As3F18; cela unitária é cúbica, a = 18,000 (3)&#197e V = 5832 (3)&#1973; grupo espacial: F23 número - 196 da Internacional Tables For X-Ray Crystallography; número de moléculas por cela unitária: Z = 4; coeficiente de absorção de massa para radiação de molibdênio: &#181; (MoK&#945)=27,4 cm-1; densidade calculada: Dc = 1,60 g.cm-3 Para um cristal de tamanho aproximadamente 0,25 x 0,25 x 0,30mm foram medidas 2309 reflexões. A média das intensidades das reflexões equivalentes por simetria de Laue foi calculada obtendo-se um total de 841 independentes, das quais, apenas 277 resultaram maiores que três vezes o desvio padrão estimado de contagem estatística. A estrutura se mostrou altamente desordenada e o modelo proposto refinou a um fator-R final de 13.8%. Os átomos de európio e arsênio estão localizados em posições especiais de simetria pontual local 23 (T) O Eu3+ está hexacoordenado através dos oxigênios das moléculas de TMU formando um octaedro regular de simetria pontual Oh. A distância európio-oxigênio é de aproximadamente 2,28 &#197. [Ln (H2O)9] (CF3SO3)3, Ln=Nd or Ho. Fórmula química: LnC3H18O18F9S3; cela unitária hexagonal a=13,851 (4)&#197, c=7,460(3)&#197 e V=1240(1) &#1973 para Ln = Nd, e a=13,570 (2)&#197, c=7,577 (1)&#197 e V=1208,5 (9)&#1973 para Ln=Ho; grupo espacial: P63/m número 176 da Internacional Tables For X-Ray Crystalography; número de moléculas por cela unitária: Z=2; coeficiente de absorção de massa para radiação de molibdênio: &#181; (MoK&#945) = 23,2 cm-1(Nd) e 34,8 cm-1 (ho); densidade calculada: Dc=2,02 g.cm-3 e 2,13 g.cm-3 respectivamente para Ln = Nd e Ho. De um cristal de forma cilíndrica de diâmetro e altura aproximadamente de 0,20 mm foram medidas 2098 reflexões para o complexo de Nd e 2400 para o de Ho. Após o calculo de média das reflexões equivalentes de Laue, obteve-se para o caso de Nd 685 reflexoes independentes das quais 636 com I &#62 3&#963(I) e o fator-R final foi 2,64%. Para o complexo de holmio as figuras foram: 763 reflexões independentes, 676 com I &#62 3&#963(I) e fator-R de 2,18%. Em ambos os casos as estruturas foram resolvidas pelos métodos de Patterson e do átomo pesado. As estruturas se mostraram isomorfas com a única diferença significativa sendo a distância lantanídeo-oxigênio de 2,49 &#197 para Nd e 2,42 para Ho. O íon lantanídeo é nonacoordenado através dos oxigênios das moléculas de água formando um prisma trigonal triencapuçado de simetria pontual cristalografica D3h. Todas as distâncias interatômicas estão dentro da faixa esperada, com exceção das distâncias C-F em ambos os casos que são um pouco curtas (1,31 &#197) / We describe here the X-ray determination of the crystal and molecular structures of three lanthanide complexes. The work is a contribution to the study of the coordination chemistry of lanthanide ions with organic ligands and in particular, it-aims to compare the observed point symmetry of the ion environment with spectroscopic predictions. The diffraction measurements were all performed on a four circle diffractometer of kappa geometry. The relevant crystal data are: Chemical formula: [Eu (TMU)6] (AsF6)3, TMU = C5H12N2O; cubic unit cell a = 18,000 (3)&#197e V = 5832 (3)&#1973; space group: F23 number 196 from International Tables for X-ray Crystallography; number of molecules per unit cell: Z = 4; mass absorption coefficient for molybdenum radiation: (MoK&#945)=27,4 cm-1; calculated density: Dc = 1,60 g.cm-3. For a crystal of approximately 0.25 x 0.25 x 0.30 mm size, 2309 reflections were measured. After averaging the intensities of the Laue-equivalent reflection, 841 independent reflections were obtained, from which only 277 had intensities greater than three times the respective standard deviations estimated from counting statistics. The structure turn out to be highly disordered and the proposed model refined to a final R-factor of 13.8%. The europium and arsenic atoms are sited on special positions of local point symmetry 23 (T). The Eu3+ is hexacoordinated to six TMU oxygen atoms, forming a regular crystallographic octahedron of point symmetry Oh. The europium oxygen distance is 2.28&#197. [Ln (H2O)9] (CF3SO3)3, Ln=Nd or Ho. Chemical formula: LnC3H18O18F9S3 hexagonal unit a=13,851 (4)&#197, c=7,460(3)&#197 and V=1240(1) &#1973 for Ln = Nd, and a=13,570 (2)&#197, c=7,577 (1)&#197 e V=1208,5 (9)&#1973 for Ln=Ho; spacial group: P63/m number 176 from International Tables for X-ray Crystallography number of molecules per unit cell: Z=2; mass absorption coefficient for molybdenum radiation: &#1810 (MoK&#945) = 23,2 cm-1 for Ln=Nd and 34,8 cm-1 for Ln=Ho; calculated density: Dc=2,02 g.cm-3 e 2,13 g.cm-3 respectively for Nd and Ho. From a cylindrically shapped crystal of approximate diameter and height of 0.20 mm, 2098 reflections for the Nd and 2400 for the Ho complexes were measured. After averaging the intensi ties of the Laue-equivalent reflections we obtain for Nd 685 independent reflections of which 636 with I &#62 3&#963(I) and agreement factor of 2.64%. For the holmium complexes the figures were 763 independent reflections, 676 with I &#62 3&#963(I) and agreement factor equal to 2.18%. In both cases the structures were solved by the heavy-atom Patterson method. The structures turn out to be isomorphous with the only significant difference of the lanthanide oxygen distances which was 2.49&#197 for Nd and 2.42&#197 for Ho. The lanthanide ions are nine-coordinated to the oxygen atom of water molecules, which form a tricapped trigonal prism of crystallographic point symmetry D3h. All interatomic distances lie within the expected normal range except the C-F ones which are somewhat shorter (1,31 &#197)

Este trabalho apresenta a síntese, caracterização e estudo fotoluminescente de nanopartículas à base de óxido misto de estanho e titânio dopadas com európio, térbio e neodímio visando à utilização como marcadores luminescentes em sistemas biológicos. As sínteses foram feitas pelos métodos de coprecipitação, sol-gel proteico e Pechini e as partículas foram caracterizadas por espectroscopia de infravermelho, análise termogravimétrica, microscopia eletrônica de varredura, difração de raios X e espectroscopia de absorção de raios X. Os estudos das propriedades fotoluminescentes foram realizados para os luminóforos dopados com európio, térbio e neodímio, sintetizados pelo método de coprecipitação. Para o luminóforo dopado com európio foi possível calcular os parâmetros de intensidade e o rendimento quântico e este apresentou resultados satisfatórios. Tratando-se de uma marcação em sistemas biológicos fez-se necessário a funcionalização destas partículas para que as mesmas se liguem à parte biológica a ser estudada. Sendo assim, funcionalizou-se as nanopartículas pelos métodos de microondas e Stöber e caracterizou-se por espectroscopia de infravermelho, microscopia eletrônica de varredura, espectroscopia por dispersão de energia e difração de raios X, obtendo-se resposta qualitativa da eficácia da funcionalização. O método espectroscópico da ninidrina foi utilizado para a quantificação da funcionalização dos luminóforos. Os estudos fotoluminescentes das partículas funcionalizadas demonstram a viabilidade do uso destes luminóforos como marcadores luminescentes. / This work presents the synthesis, characterization and photoluminescent study of tin and titanium mixed oxide nanoparticles doped with europium, terbium and neodymium to be used with luminescent markers on biological systems. The syntheses were done by co-precipitation, protein sol-gel and Pechini methods and the nanoparticles were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction and X-ray absorption spectroscopy. The photoluminescent properties studies were conducted for luminophores doped with europium, terbium and neodymium synthesized by coprecipitation method. For luminophore doped with europium it was possible to calculate the intensity parameters and quantum yield and it showed satisfactory results. In the case of biological system marking it was necessary the functionalization of these particles to allow them to bind to the biological part to be studied. So the nanoparticles were functionalized by microwave and Stöber methods and characterized by infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction obtaining qualitative response of functionalization efficacy. The ninhydrin spectroscopic method was used for quantification of luminophores functionalization. The photoluminescent studies of functionalized particles demonstrate the potential applying of these luminophores as luminescent markers.

Commercial longline fishing results in large amounts of incidental bycatch of elasmobranch fishes (sharks, skates, and rays). Teleost species lack electrosensory systems and development of technologies which target the ampullary organs of sharks provides an avenue to selectively deter elasmobranchs without affecting the catch rate of target teleosts. Electric field measurements and a controlled scientific longline study were conducted testing whether the lanthanide metal neodymium or zinc/graphite might reduce elasmobranch catch per unit effort (CPUE). Baited longline hooks were treated with neodymium and zinc/graphite and catch rates were compared to that of controls. Shark CPUE decreased by 60% on neodymium treated hooks and 80% on zinc/graphite treated hooks. The effectiveness of both treatments varied among species with significant reductions shown for Atlantic sharpnose sharks (Rhizoprionodon terranovae) but less dramatic differences for others. Zinc/graphite is potentially a viable tool for reduction of shark bycatch in a commercial longline fishery. / by Kieran Thomas Smith. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Sharks comprise a large portion of bycatch in pelagic longline fisheries worldwide. Lanthanide metals have been proposed as shark repellents. This study quantified the normalized voltage of lanthanide metals in seawater and found that there was no difference in normalized voltage among the six tested metals. Temperature and salinity had a significant effect on lanthanide normalized voltage. The output at 18ºC was significantly greater than at both 12 and 24ºC. The normalized voltage was significantly greater in freshwater than brackish or seawater. The dissolution rate for the lanthanides varied from -1.6 to -0.2g/h. As the metals dissolved the voltage remained constant. In a behavioral assay, neodymium was ineffective at repelling bonnethead sharks (Sphyrna tiburo) tested individually and in groups, and lemon sharks (Negaprion brevirostris) in groups. Due to high cost, fast dissolution rates, and lack of deterrent effects, lanthanide metals are not recommended for use in mitigating shark bycatch. / by Sara M. McCutcheon. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.