Compounds containing multiple metal-carbon bonds are now widely used as catalysts for organic and materials synthesis. Among such transformations, olefin metathesis (OM) occupies a position of pre-eminent significance. Alkyne metathesis holds great promise, but remains in a much lower state of development. The OM-directed work in this thesis sought to advance the state of the art in living, Ru-catalyzed ringopening metathesis polymerizations (ROMP). Currently, the first- and third-generation Grubbs initiators, which exhibit the ease of handling characteristic of the late metal ruthenium, dominate ROMP applications. These initiators are characterized by extremes of reactivity, however. We describe the first ruthenium initiator capable of living ROMP at RT, irrespective of monomer bulk. Polydispersity indices as low as 1.03 are routinely attainable, and excellent control is maintained in synthesis of diblock copolymers from sterically demanding and sterically unencumbered monomers. Work on alkyne metathesis sought to expand existing understanding of the features that influence stability and reactivity in ruthenium carbynes. A classification system was developed in which Class A carbynes were defined as those that readily undergo conversion into an M=C entity (e.g. vinylidene, allenylidene, or alkylidene); Class B carbynes those that have a stable carbyne functionality. Four Ru carbyne complexes, all initially regarded as prospective Class B carbynes, were selected for study. Investigation of their reactivity resulted in categorization of several as Class A species, and development of design criteria that may open the door to assembly of stable, well-defined carbyne complexes of ruthenium.

Optimized methods for the regioselective and stereospecific synthesis of both trisubstituted and tetrasubstituted olefins as single isomers from E-β-chloro-α-iodo-α,β-unsaturated esters have been developed from previous work done in the Ogilvie lab. These optimized methods have led to the synthesis of trans isomeric enediynes that can be photoisomerized to their respective cis isomers and subsequently undergo microwave-assisted Bergman cycloaromatizations. Furthermore, both cis and trans isomeric enediynes that have propargyl ether substituents have been found to be able to undergo photoactivated Bergman cyclizations without the need for an intermolecular hydrogen donor. A mechanism study has confirmed that the Bergman cyclization products that form without the presence of an intermolecular hydrogen donor undergo a series of 1,5-hydrogen shifts as intermediates. A series of optimizations to these reactions were carried out, in part by utilizing electron-donating or electron-withdrawing functional groups to help stabilize the resulting radicals that form on the intermediates, and thus increase the yield of the associated Bergman cyclization products.

A new analytical technique to measure the chemical composition distribution (CCD) of polyolefins, crystallization elution fractionation (CEF), was introduced in 2006 during the First International Conference on Polyolefin Characterization. CEF is a faster and higher resolution alternative to the previous polyolefin CCD analytical techniques such as temperature rising elution fractionation (TREF) and crystallization elution fractionation (CRYSTAF) (Monrabal et al., 2007). Crystallization elution fractionation is a liquid chromatography technique used to determine the CCD of polyolefins by combining a new separation procedure, dynamic crystallization, and TREF. In a typical CEF experiment, a polymer solution is loaded in the CEF column at high temperature, the polymer is allowed to crystallize by lowering the solution temperature, and then the precipitated polymer is eluted by a solvent flowing through the column as the temperature is raised. CEF needs to be calibrated to provide quantitative CCD results. A CEF calibration curve consists of a mathematical relationship between elution temperature determined by CEF and comonomer fraction in the copolymer that could be estimated by Fourier transform infrared spectroscopy (FTIR) and carbon-13 nuclear magnetic resonance (13C NMR). Different comonomer types in ethylene/α-olefin copolymers will have distinct calibration curves. The main objective of this thesis is to obtain CEF calibration curves for several different ethylene/α-olefin copolymers and to investigate which factors influence these calibration curves. A series of homogeneous ethylene/α-olefin copolymers (1-hexene, 1-octene and 1-dodecene) with different comonomer fractions were synthesized under controlled conditions to create CEF calibration standards. Their average chemical compositions were determined by 13C NMR and FTIR and then used to establish CEF calibration curves relating elution temperature and comonomer molar fraction in the copolymer.

Compounds containing multiple metal-carbon bonds are now widely used as catalysts for organic and materials synthesis. Among such transformations, olefin metathesis (OM) occupies a position of pre-eminent significance. Alkyne metathesis holds great promise, but remains in a much lower state of development. The OM-directed work in this thesis sought to advance the state of the art in living, Ru-catalyzed ringopening metathesis polymerizations (ROMP). Currently, the first- and third-generation Grubbs initiators, which exhibit the ease of handling characteristic of the late metal ruthenium, dominate ROMP applications. These initiators are characterized by extremes of reactivity, however. We describe the first ruthenium initiator capable of living ROMP at RT, irrespective of monomer bulk. Polydispersity indices as low as 1.03 are routinely attainable, and excellent control is maintained in synthesis of diblock copolymers from sterically demanding and sterically unencumbered monomers. Work on alkyne metathesis sought to expand existing understanding of the features that influence stability and reactivity in ruthenium carbynes. A classification system was developed in which Class A carbynes were defined as those that readily undergo conversion into an M=C entity (e.g. vinylidene, allenylidene, or alkylidene); Class B carbynes those that have a stable carbyne functionality. Four Ru carbyne complexes, all initially regarded as prospective Class B carbynes, were selected for study. Investigation of their reactivity resulted in categorization of several as Class A species, and development of design criteria that may open the door to assembly of stable, well-defined carbyne complexes of ruthenium.

Submitted by Gustavo Nascimento (gustavo.diniz@ufcg.edu.br) on 2018-02-02T11:24:55Z No. of bitstreams: 1 KALINE ROSÁRIO MORAIS FERREIRA - TESE PPGCMAT 2014.pdf: 4196427 bytes, checksum: cfa12a2731146e96138a50d4de35c10e (MD5) / Made available in DSpace on 2018-02-02T11:24:55Z (GMT). No. of bitstreams: 1 KALINE ROSÁRIO MORAIS FERREIRA - TESE PPGCMAT 2014.pdf: 4196427 bytes, checksum: cfa12a2731146e96138a50d4de35c10e (MD5) Previous issue date: 2014-08-29 / CNPq / Neste trabalho nanocompósitos à base de olefina termoplástica (TPO) formados pela mistura polipropileno (PP)/terpolímero de etileno-propileno-dieno (EPDM)/argila organofílica foram preparados pelo processo de intercalação por fusão. As TPOs, não compatibilizadas e compatibilizadas com polipropileno modificado com anidrido maleico (PP-g-MA), foram preparadas em um misturador interno de laboratório, empregando duas razões de PP/EPDM: 90:10 e 70:30. A estas TPOs foram incorporadas cinco tipos de argila organofílica em teores de 1, 3 e 5 pcr. A influência da razão PP/EPDM, da presença do compatibilizante orgânico (PP-g-MA), do tipo e do teor de argila na morfologia e propriedades mecânicas em tração destas TPOs foi avaliada. Os resultados obtidos por difratometria de raios X (DRX) sugerem que a adição de 1, 3 e 5 pcr das argilas organofílicas às TPOs, independente do tipo, resulta na formação de nanocompósitos com estrutura possivelmente intercalada desordenada e que as TPOs contendo as argilas organofílicas preparadas com tecnologia local apresentaram resultados semelhantes àquelas com argila organofílica comercial empregada como padrão de comparação para este estudo. Os dados de DRX mostraram também que a fase cristalina do polipropileno foi alterada pela presença do agente compatibilizante. A morfologia das TPOs, conforme dados de microscopia eletrônica de varredura (MEV), foi afetada pela razão PP/EPDM, pela presença do compatibilizante orgânico e pelo tipo e teor de argila. As TPOs com proporção PP/EPDM de 90:10, não compatibilizadas com PP-g-MA e com teor de argilas de 3 pcr apresentaram superfícies de fratura criogênica isentas de vazios. Para estas TPOs quatro das cinco argilas organofílicas estudadas atuaram como compatibilizantes para as misturas PP/EPDM favorecendo a forte interação entre fases, o que resultou no aumento da resistência à tração da referida TPO. Da mesma forma que a argila comercial, três das quatro argilas organofílicas v preparadas com tecnologia local foram efetivas em compatibilizar e, consequentemente, em aumentar a resistência mecânica em tração da TPO PP/EPDM 90:10, quando empregadas no teor de 3 pcr. Isto indica que é possível utilizar argilas organofílicas em substituição de compatibilizantes orgânicos (poliméricos ou oligoméricos) para aumentar a interação interfacial entre PP e EPDM. O PP-g-MA e as argilas organofílicas (independente do tipo e do teor) não favoreceram a compatibilização da TPO PP/EPDM 70:30; por esta razão as propriedades de resistência à tração destas foram inferiores aos da TPO sem argila ou sem compatibilizante orgânico. / In this work nanocomposites based on a thermoplastic olefin (TPO) formed by blending polypropylene (PP), ethylene-propylene-diene (EPDM), and organoclay were prepared by melt intercalation process. The TPOs, non-compatibilized and compatibilized with PP modified with maleic anhydride (PP-g-MA), were prepared in a laboratory internal mixer, employing two ratios PP/EPDM: 90:10 and 70:30. To these blends, five types of organoclay were incorporated, in amounts of 1, 3 and 5 phr. The influence of PP/EPDM ratio, the presence of organic compatibilizer (PP-g-MA), and the type and amount of clay in the morphology and tensile mechanical properties of theTPO was evaluated. The results obtained by X-ray diffractometry (XRD) suggest that the addition of organoclays, regardless of type, result in the formation of nanocomposites, possible disorderly sandwiched structures, and that the organoclays prepared with local technology showed similar results to those with commercial organoclay, employed as a standard of comparison in this study. The XRD data also showed that the crystalline phase of polypropylene was modified by the presence of coupling agent. The morphology of the TPO, as electron microscopy (SEM) data shows, was affected by the ratio PP/EPDM, the presence of organic compatibilizer, and the type and content of organoclay. The TPO with a proportion PP/EPDM 90:10, not compatibilized, and with 3 phr clay showed void-fee cryogenic fracture surfaces. For this TPO, four of the five organoclays studied acted as compatibilizers for the PP/EPDM mixture, favoring the strong interaction between phases, which resulted in increasing tensile strength. Similar to the commercial clay, three of the four organoclays prepared with local technology were effective as blend compatibilizers and increased the mechanical strength of the composite PP/EPDM 90:10 with 3 phr organoclay content. These findings suggest that organoclays may replace organic compatibilizers (polymeric or oligomeric) to increase the interfacial interaction vii between PP and EPDM. The PP-g-MA and organoclay (regardless of the type and content) did not favor promoted strong PP/EPDM interactions in 70:30 blend; for this reasons, tensile strength was lower than those of TPO without clay or organic without compatibilizer.

La préparation efficace d’une nouvelle famille de sels de 1,3-bis(aryl)-4,5-dihydroimidazolium non symétriques comprenant un groupement encombrant hexafluoroisopropylmethoxy en position para- ou ortho- sur l’un des substituants N-aryle a été développée. De nouveaux sels d’imidazolium contenant un substituant fluoroalkyle en position ortho d’un des substituant aryle ont aussi été synthétisés. Ces sels sont d’excellents précurseurs de carbènes N-hétérocycliques qui ont permis l’accès efficace à une série de nouveaux complexes carbéniques du ruthénium à ligands NHC non symétriques. La méthode repose sur la génération in situ du carbène par traitement des sels d’imidazolium avec le potassium hexamethyldisilazide suivie d’un échange du ligand tricyclohexylphosphine à partir des complexes de Grubbs et Hoveyda de première génération. L’activité de ces nouveaux complexes a été étudiée sur des réactions modèles intra- et intermoléculaires de métathèse des oléfines. Il a été montré que la plupart des complexes synthétisés ont de bonnes activités catalytiques en fermeture de cycle à partir du diallylmalonate d’éthyle et en métathèse croisée de l’allylbenzène avec le 1,3-diacetoxybut-2-ene. Leurs performances sont comparables à celles des catalyseurs de Grubbs et Hoveyda de seconde génération, avec toutefois quelques différences dans les étapes d’initiation. Les effets structuraux et électroniques des ligands NHC non symétriques sur la réactivité des nouveaux complexes du ruthénium ont été étudiés. En particulier, il a été montré que les catalyseurs de type Hoveyda porteurs de ligands monosubstitués par un groupement fluoroalkyle en position ortho d’un des substituant N-aryle présentent une initiation très rapide dans les réactions de métathèse croisée. Au contraire, les complexes porteurs d’un groupement donneur alkyle ont montré une activité catalytique très faible, comme par exemple le complexe porteur d’un ligand (tert-butyl)NHC qui s’est révélé inerte à la fois en fermeture de cycle et métathèse croisée. Les complexes porteurs d’un ligand NHC symétrique avec deux groupes hexafluoroisopropylmethoxy ont des activités catalytiques nettement inférieures à leurs homologues non symétriques, révélant ainsi la forte influence de l’absence de symétrie du ligand carbène NHC dans l’activité catalytique des complexes. / An efficient approach to a new family of unsymmetrical 1,3-bis(aryl)-4,5-dihydroimidazolium salts comprising bulky hexafluoroisopropylmethoxy group in para- or ortho-position in one of the N-aryl substituents has been developed. New imidazolinium salts with fluoroalkyl-containing mono-ortho-aryl substituent at one of the nitrogen atom have also been synthesized. It was found that these imidazolinium salts are effective NHC precursors and provided an efficient access to a series of new ruthenium carbene complexes with unsymmetrical fluorinated NHC ligands. The method involves in situ generation of the carbene via treatment of the starting salts with potassium hexamethyldisilazide and subsequent ligand exchange reaction with PCy3-containing first generation Grubbs and Hoveyda complexes. The catalytic activity of the new complexes has been investigated on model reactions of intra- and intermolecular olefin metathesis. It was found that most of the synthesized complexes exhibited high activity in cyclization of diethyl diallylmalonate and in cross metathesis of allyl benzene with 1,3-diacetoxybut-2-ene. Their performance has proved to be comparable with commonly used second generation Grubbs and Hoveyda catalysts, with sometimes some differences in the initiation step. Structural and electronic impact of fluorinated unsymmetrical NHC on reactivity of new ruthenium complexes has been studied. In particular, it was revealed that Hoveyda type catalysts with mono-ortho-aryl substituted NHC ligands have demonstrated very high initiation rate in CM reactions. On the contrary, catalysts with more donating N-alkyl NHCs have displayed low activity; for instance, the N-tert-butyl substituted complex has proved to be absolutely inert both in RCM and CM reactions. Symmetrical ruthenium carbene complexes bearing NHC ligands with two hexafluoroisopropylmethoxy group in para-positions of N-aryl moieties are significantly inferior in reactivity with respect to their asymmetric counterparts showing the strong influence of the desymmetrization factor on catalytic activity.

Os complexos do tipo [RuCl2(PPh3)2amina], amina = pip (1) ou pep (2), foram estudados como iniciadores catalíticos para reações de ROMP de NBE, NBD e oxaNBE-OMe e na ROMCP de NBE com NBD e oxaNBE-OMe com NBE. O complexo [RuCl2(PPh3)(pep)(isn)] (3) foi estudado na ROMP de NBE e NBD. Os complexos 2 e 3 são inéditos e suas caracterizações são discutidas e correlacionadas com o complexo com 1. As reações de catálises foram realizadas com variações de tempo, volume de solvente e temperatura, em atmosfera de Ar ou ar e na presença de EDA. <br />O rendimento foi quantitativo na ROMP de NBE com o complexo 1 em 2 mL de CHCl3, por 5 min a 25 &deg;C em Ar, com IPD de 1,9 e Mw na ordem de 106 g mol-1. Com o complexo 2, os rendimentos foram quantitativos (IPD ~ 3 e Mw na ordem de 104 g mol-1) e independentes do tempo (5 -120 min) e volume de solvente (2 - 8 mL). Com 3, os rendimentos diminuíram com o aumento do volume de solvente, mas com IPD ~ 2 e Mw na ordem de 104 g mol-1. Em todos os casos os rendimentos diminuíram em atmosfera de ar e com polímeros polimodais. <br />Rendimentos quantitativos de poliNBD foram obtidos com 1 a 40 &deg;C e com 2 a 25 &deg;C na faixa de volume de solvente estudada, por 60 e 120 min, em Ar. Os rendimentos com 3 foram inferiores a 35%. Foram também obtidos rendimentos quantitativos em atmosfera de ar em certas combinações de tempo e volume de solvente, indicando que os complexos são robustos para atividades em soluções contendo O2. Todos os polímeros de NBD foram insolúveis. <br />Obteve-se até 70% de poli(NBE-co-NBD) isolado a partir de reações com 1 e reações quantitativas com 2, dependendo da fração molar NBE:NBD usada, indicando as razões de reatividades do complexos. <br />A ROMP de oxaNBE-OMe com 1 ou com 2 formou 15 a 30% de rendimento, a 40 &deg;C por 24 h em Ar. Na ROMCP desse monômero com NBE obteve-se de 5 a 30% de rendimento, dependendo da fração molar. Os rendimentos são maiores nas frações molares com maior quantidade de NBE. Poli(oxaNBE-OMe) foi solúvel, enquanto que seus copolímeros foram pouco solúveis. <br />São realizadas discussões quantos às características eletrônicas e de impedimentos estéricos nos complexos estudados nas polimerizações via metátese, selecionando-se os ligantes ancilares frente às condições de reações para obtenções de bons rendimentos e características dos polímeros isolados. / The complexes of type [RuCl2(PPh3)2amina], amine = pip (1) or pep (2), were studied as catalytic initiators for ROMP of NBE, NBD and oxaNBE-OMe and for ROMCP of NBE with NBD and oxaNBE-OMe with NBE. The complex [RuCl2(PPh3)(pep)(isn)] (3) was studied for ROMP of NBE and NBD. The complexes 2 and 3 are novels and their characterizations are discussed and correlated with the complex 1. The catalysis reactions were performed with variations of time, volume of solvent and temperature, either in Ar or air atmosphere, in the presence of EDA. <br />The yield was quantitative for ROMP of NBE with complex 1 in 2 mL of CHCl3 for 5 min at 25 &deg;C in Ar, with PDI of 1.9 and Mw in the order of 106 g mol-1. With the complex 2, the yields were quantitatives (PDI ~ 3 and Mw in the order of 104 g mol-1) and independent of time (5 - 120 min) and volume of solvent (2 - 8 mL). With 3, the yields decreased when increasing the volume of solvent, but with PDI ~ 2 and Mw in the order of 104 g mol-1. In all the cases, the yields decreased in air atmosphere with polymodal polymers. <br />Quantitative yields of poliNBD were obtained with 1 at 40 &deg;C and with 2 at 25 &deg;C in the range of the studied volume of solvent, for 60 and 120 min, in Ar. The yields with 3 were less than 35%. Quantitative yields were also obtained in air atmosphere in some combinations of time and volume of solvent, indicating that the complexes are robust for activities in solutions containing O2. All polyNBD were insoluble. <br />It was obtained up to 70% of poly(NBE-co-NBD) isolated from reactions with 1 and quantitative reactions were obtained with 2, depending on the NBE:NBD molar fraction used, indicating the reactivity ratios for the complexes. <br />The ROMP of oxaNBE-OMe with 1 or with 2 yielded 15 to 30% at 40 &deg;C for 24h in Ar. In the ROMCP of this monomer with NBE, it was obtained from 5 to 30% yield, depending on the molar fraction. Yields are higher in molar fractions with higher amount of NBE. Poly(oxaNBE-OMe) was soluble, while its copolymers were poorly soluble. <br />Discussions are held on the electronic characteristics and steric hindrances in the studied complexes for the metathesis polymerization, selecting the ancillary ligands as a function of the reaction conditions to obtain good yields and to improve the characteristics of the isolated polymers.

As moléculas de 4-CH2X-piperidinas, X = OH (1), H (2) e Ph (3) foram investigadas como ligantes ancilares nos novos complexos [RuCl2(PPh3)2(4-CH2X-pip)] para a polimerização via metátese por abertura de anel (ROMP) de norborneno (NBE) e norbornadieno (NBD). Os complexos foram obtidos pela síntese com [RuCl2(PPh3)3] e caracterizado por análise elementar de CHN, infravermelho e RMN 31P {1H}. Os resultados sugeriram moléculas pentacoordenadas com ambos os íons cloreto e ambos os ligantes fosfinas trans-posicionados em uma geometria pirâmide de base quadrada em cada caso; a amina está no eixo axial.<br /> ROMP de NBE com 1 foram realizadas em argônio em função do volume de etildiazoacetato (EDA; 2 - 8 &micro;L), razão molar [NBE]/[Ru] (1.000 - 10.000), tempo ( 5 - 60 minutos) e temperatura (25 e 50 &deg;C) para obter a melhor condição de reação. Com 2 &micro;L de EDA a 50 &deg;C por 30 minutos e [NBE]/[Ru] = 5000, poliNBE foi quantitativamente isolado com Mw = 20,6 x 104 e IPD = 2,2. Em condições similares, rendimentos de 80 e 83% foram obtidos com 2 e 3, respectivamente (Mw = 2,4 x 104 e 0,2 x 104; IPD = 2,3 e 1,8). Os rendimentos em presença de PPh3 em excesso (20 equivalentes) foram reduzidos para 18 - 32%, enquanto na presença de amina (20 equivalentes) o complexo foi totalmente inativo. É sugerido que as reações de ROMP ocorrem quando o ligante PPh3 abandona a esfera de coordenação do Ru, e a amina em excesso envenena o catalisador devido à forte coordenação &sigma;. Experimentos com NBE em ar atmosférico resultaram em 68-77% de rendimentos, sugerindo boa resistência dos complexos à oxidação com O2.<br /> Os rendimentos para a ROMP de NBD foram de 100, 54 e 73% para 1, 2 e 3 respectivamente, utilizando as mesmas condições. Os poliNBD foram insolúveis em CHCl3. Poli[NBE-co-NBD] foram obtidos com 57 - 71% de rendimento com cada um dos complexos em presença de diferentes frações molares de comonômeros. / The molecules 4-CH2X-piperidines, X = OH (1), H (2) e Ph (3) were investigated as ancillary ligands in the new [RuCl2(PPh3)2(4-CH2X-pip)] complexes for ring opening metathesis polymerization (ROMP) of norbornene (NBE) and norbornadiene (NBD). The complexes were obtained from syntheses with [RuCl2(PPh3)3] and characterized by CHN elementary analyses, infrared and 31P-NMR. The results suggested penta-coordinated molecules with both chloro and both phosphine ligands trans-positioned in a square pyramid geometry in each case; the amine is the axial axis.<br /> ROMP of NBE with 1 were carried out in argon atmosphere in a function of ethyldiazoacetate volume (EDA; 2 - 8 &micro;L), [NBE]/[Ru] molar ration (1,000 - 5,000), time (5- 60 min) and temperature (25 and 50 &deg;C) to obtain the best reaction conditions. With 2 &micro;L of EDA at 50 &deg;C for 30 min and [NBE]/[Ru] = 5,000, polyNBE was quantitatively isolated with Mw = 20,6 x 104 e IPD = 2,2. In similar conditions, yields of 80 and 83% were obtained with 2 e 3, respectively (Mw = 2,4 x 104 and 0,2 x 104; PDI = 2,3 and 1,8). The yields in presence of PPh3 in excess (20 equivalents) were reduced to 18 - 32%, whereas in presence of amine (20 equivalents) the complexes were totally inactive. It is suggested that the ROMP reactions occurs when a PPh3 ligand leaves the Ru coordination sphere and the amine in excess poison the catalyst due to a strong &sigma;-coordination. Experiments with NBE in atmospheric of air resulted in 68-77% yields, suggesting good O2-resitances of the complexes to oxidation.<br /> The yields for ROMP of NBD were 100, 54 and 73% with 1, 2 e 3, respectively, under the same conditions. The polyNBD were insolubles in CHCl3. Poly[NBE-co-NBD] were obtained with 57 - 71% yield with either one of the complexes in presence of different comonomer molar fractions.

Orientadores: Daniela Zanchet, Regina Buffon / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T08:37:31Z (GMT). No. of bitstreams: 1 Aragao_IsaiasBarbosa_M.pdf: 4247291 bytes, checksum: 09937fc60abf375cebc0a59dc22ae39a (MD5) Previous issue date: 2014 / Resumo: Nanopartículas (NPs) e os ligantes em sua superfície vêm ganhando espaço como meio suporte devido a suas propriedades que aliam o comportamento da catálise homogênea com a heterogênea. Em longo prazo, imagina-se que o controle do ambiente local de espécies ancoradas na superfície destas NPs possa mimetizar o sítio catalítico de enzimas. Visando explorar a influência do ambiente local, foi avaliado o desempenho do catalisador de Grubbs de primeira geração em duas condições: encapsulado em matriz de sílica e na presença de NPs de ouro (NPs-Au). Apesar das reações de encapsulamento pelo método sol-gel serem rotas bastante exploradas, os resultados não foram encorajadores devido à desativação do complexo de rutênio nas condições de formação do gel, tanto pela via hidrolítica quanto não-hidrolítica. Com relação às NPs-Au, elas foram sintetizadas com misturas de ligantes (1-octanotiol e ácido 3-mercaptopropiônico), mostrando separação de fases dos ligantes, com a formação de domínios (raias). Nos estudos com catalisador de Grubbs em reações de metátese (autometátese do 1-hexeno e polimerização por abertura de anel do 1,5-ciclooctadieno), tanto a presença das NPs-Au como a de tiol livre tiveram influência negativa, levando a sua desativação prematura. Na presença de NPs-Au, houve queda da atividade, chegando a conversões nulas para razões mássicas maiores de que 1 mg de ouro/10 mg de catalisador, estando possivelmente associado à complexação das mercaptanas das NPs-Au com o complexo de rutênio. Buscando viabilizar o ancoramento do catalisador nas NPs-Au, sintetizou-se um ligante carbeno NHC com a funcionalização do esqueleto carbônico posterior do anel com um grupamento alil, que representa a primeira etapa para introdução de grupos funcionais e ancoramento em NPs / Abstract: The use of nanoparticles (NPs) and their protecting layer as support in catalysis start to be exploited, due to their unique characteristics at the interface of homogeneous and heterogeneous catalysts. At long term, the tuning of the local environment of catalytic species anchored on the surface of NPs may be a way to mimic the active site of enzymes. Aiming to explore the influence of the local environment, we evaluated the activity of the first generation Grubbs catalyst under two conditions: encapsulating it in a silica matrix and in the presence of gold NPs (NPs-Au). Although the heterogenization via the sol-gel method is a well-known and well-explored route, we could not obtain good results due to catalyst deactivation under gel formation in both hydrolytic and non-hydrolytic (nonaqueous) conditions. Considering the NPs-Au, they were synthesized with success using a mixture of ligands (1-octanethiol and 3-mercaptopropionic acid) that showed phase segregation and formation of stripes. The evaluation of the Grubbs catalyst on metathesis reactions (self-metathesis of 1-hexene and ring opening polymerization of 1,5-ciclooctadiene) showed premature deactivation in the presence of both NPs-Au and free thiol. In the presence of NPs-Au, the catalytic activity descreased, achieving null results when weight ratios bigger than 1mg of NPs-Au to 10 mg of catalyst were used, possibly associated to the interaction between the mercaptans and the ruthenium catalyst. To make possible the catalyst anchoring on the NPs-Au surface, a NHC carbene with an allyl group on its carbon backbone was synthesized, corresponding to the first step to introduce functional groups to the catalyst / Mestrado / Quimica Inorganica / Mestre em Química

L’objectif de cette thèse est de synthétiser des nanoparticules dans des microsystèmes en copolymère d’oléfine cyclique (COC), en vue du développement d’une nouvelle phase stationnaire de chromatographie présentant des performances améliorées. Dans un premier temps, la base théorique du projet est présentée. Les performances chromatographiques d’une colonne en fonction de la taille des particules qui la constituent sont présentées, en termes de résolution et d’efficacité, ainsi qu’en temps d’analyse. L’utilisation de nanoparticules s’avère optimale, mais l’état de l’art sur les différents types de colonnes et de modes de séparations en microsystèmes montre la difficulté technique de cet objectif. Les différentes voies de synthèse de nanoparticules par polymérisation radicalaire en micro et miniémulsion sont ensuite détaillées. Les essais préliminaires ont permis de définir la méthodologie d’approche : 1) la synthèse de nanoparticules par polymérisation radicalaire en miniémulsion et 2) la fonctionnalisation indispensable des supports COC. Dans un premier temps, la composition de la miniémulsion a été optimisée par plan d’expériences. La meilleure formulation permet la synthèse, après photopolymérisation, de nanoparticules monodisperses de diamètre moyen inférieur à 200 nm. Une étude d’ancrage des nanoparticules sur plaques COC est ensuite réalisée. L’optimisation du greffage d’un monomère polyéthylène glycol diacrylate (PEGDA) est réalisée par plan d’expériences. La synthèse photochimique des nanoparticules sur des surfaces COC fonctionnalisées PEGDA permet l’obtention de nanoparticules sphériques et monodisperses de taille inférieure à 200 nm répondant parfaitement au cahier des charges. Ce travail constitue une première étape dans la réalisation de phases stationnaires innovantes en chromatographie / The aim of this thesis is the synthesis of nanoparticles in cyclic olefin copolymer (COC) microchips in order to develop a new stationary phase. The bibliography review reveals the interest of this project in increasing column performance (efficiency and resolution) and reducing the analysis time. A general review on stationary phases and separation mode in microchips is presented. The synthesis of nanoparticles by radical polymerization of micro and miniemulsion is then detailed. The preliminary results helped defining the methodological approach: 1) Synthesis of nanoparticles via miniemulsion radical polymerization and 2) functionalization of COC surfaces. First, miniemulsion composition is optimized by an experimental design. The optimal miniemulsion led, after photopolymerization, to monodisperse nanoparticles with a diameter size inferior to 200 nm. The anchorage on COC surface is then investigated and shows that COC functionalization with a hydrophilic monomer is essential. Photografting of polyethylene glycol methacrylate (PEGDA) optimization is carried out by an experimental design. The UV synthesis of nanoparticles on COC surfaces functionalized by PEGDA is demonstrated. Monodisperse and spherical nanoparticles with a diameter size inferior to 200 nm are obtained. This work is considered as a first step in the development of a new stationary phase for chromatography