Orientador: Maria Isabel Felisberti / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-17T08:46:35Z (GMT). No. of bitstreams: 1 Santos_LuisEduardoPaisdos_D.pdf: 4191396 bytes, checksum: d2ee438006096211a78208eaecc89877 (MD5) Previous issue date: 2010 / Resumo: Este trabalho objetivou a síntese de copolímeros contendo grupos iônicos. Foram utilizadas diferentes rotas sintéticas para a obtenção de copolímeros de estireno (S) e ácido vinilfosfônico (AVF) (P(S-co-AVF)): 1. Copolimerização radicalar destes monômeros; 2. Copolimerização de estireno e vinilfosfonato de dimetila (VFDM) (P(S-co-VFDM)), seguida de hidrólise. Foram variadas as composições e condições de síntese. Copolímeros P(S-co- AVF) foram obtidos por polimerização radicalar em solução de dimetilformamida, utilizando peróxido de benzoíla (BPO) como iniciador. Estes copolímeros apresentaram baixo grau de inserção de AVF, entretanto, observou-se aumento da temperatura de transição vítrea (Tg), da resistência térmica e do teor de resíduos a 900°C, assim como a diminuição da massa molar com o incremento de AVF. Copolímeros P(S-co-VFDM) foram sintetizados por polimerização em solução de tolueno e em bulk, utilizando BPO como iniciador. Os copolímeros obtidos em bulk apresentaram maior inserção de VFDM, em comparação aos copolímeros obtidos em solução, partindo-se das mesmas frações molares dos monômeros, como conseqüência do maior tempo de reação para o primeiro caso. O aumento do teor de VFDM nos copolímeros causa a diminuição da massa molar, da Tg, da resistência térmica e do aumento no teor de resíduo a 900°C. Enquanto os copolímeros obtidos em bulk apresentaram degradação térmica complexa, os copolímeros obtidos em solução apresentam basicamente despolimerização. Os parâmetros de copolimerização dos monômeros S (rS) e VFDM (rVFDM) foram determinados pelos métodos de Mayo e Lewis e de Kelen e Tüdõs, sendo o parâmetro de copolimerização consideravelmente maior para o estireno (rS/rVFDM ~ 30). Os copolímeros obtidos em bulk foram hidrolisados em meio alcalino, obtendo-se ionômeros e polieletrólitos. Apesar da hidrólise não ser completa, a presença de grupos iônicos nestes copolímeros aumenta a Tg, o teor de resíduos e a complexidade da degradação térmica. / Abstract: The main purpose of this work was to synthesize copolymers with ionic groups. Different synthetic routes were applied to obtain copolymers of styrene (S) and vinylphosphonic acid (AVF) (P(S-co-AVF)): 1. Radical copolymerization of these monomers; and 2. Copolymerization of styrene and dimethyl-vinylphosphonate (VFDM) (P(S-co-VFDM)), followed by hydrolysis. The P(S-co-AVF) copolymers were obtained by radical polymerization in dimethylformamide solution using benzoyl peroxide (BPO) as an initiator. These copolymers presented low AVF insertion level. However, increase of the glass transition temperature (Tg), thermal resistance and residue at 900°C were observed. Besides, a decrease of the molar mass was observed with the increase of AVF content. P(S-co-VFDM) copolymers were synthesized by polymerization in toluene solution and in bulk, using also BPO as the initiator. The copolymers obtained by bulk polymerization presented higher VFDM insertion level than the copolymers obtained in solution, considering the same monomers molar fractions in the reactional medium. This behavior was a consequence of the higher reaction time involved in the first method. The increase of the VFDM content in the copolymers caused decreases of the molar mass, of the Tg and of the thermal resistance, and an increase of the residues level at 900°C. Moreover, the copolymers obtained in bulk presented a complex thermal degradation mechanism, while the copolymers obtained in solution presented basically a depolymerization. The copolymerization parameters of the monomers S (rS) and VFDM (rVFDM) were determined by Mayo and Lewis method and by Kelen and Tüdõs method. The copolymerization parameter of the styrene was significantly higher than the parameter of the (rS/rVFDM ~ 30). The copolymers obtained in bulk were hydrolyzed in an alkaline medium, resulting in ionomers and polyelectrolytes. Even though the hydrolysis was incomplete, the presence of the ionic groups in these copolymers has altered significantly its solubility and thermal degradation mechanism and has increased its Tg and residue level. / Doutorado / Físico-Química / Doutor em Ciências

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Asymmetric hydrogenation has emerged as a versatile methodology to obtain a wide range of chiral precursors. This thesis focused on the synthesis of new chiral ligands and the expansion of the substrate scope of asymmetric hydrogenations. Paper I described the synthesis and evaluation of N,P-ligands for the Ir-catalyzed hydrogenations of unfunctionalized olefins. The substrate scope of Ir-catalyzed asymmetric hydrogenations is limited to a narrow range of “test” olefins. The foremost focus of this thesis was to expand the substrate scope of Ir-catalyzed asymmetric hydrogenations. Papers II and III disclosed the potential of the N,P-ligated Ir complexes in hydrogenation of the enol phosphinates. This substrate class is attractive because the hydrogenated products are chiral alkylphosphinates that can be transformed into chiral alcohols and chiral phosphines without sacrificing enantiopurity. A wide range of enol phosphinates were hydrogenated to excellent conversions and enatioselectivities. The hydrogenation of purely alkyl-substituted enol phosphinates in very high conversions and ee values was emphasized in these studies. Paper IV described the investigation of unfunctionalized enamines as substrates in Ir-catalyzed hydrogenation studies. The hydrogenation results and structural limitations of the substrates are presented. Paper V described the asymmetric hydrogenation of diphenylvinylphosphine oxides, di- and trisubstituted vinyl phosphonates. The hydrogenation of diphenylvinylphosphine oxides gives direct access to protected chiral phosphines. The hydrogenated products of vinylphosphonates are highly synthetically useful in pharmaceutical and material chemistry. Hydrogenation of E/Z mixtures of carboxyethyl vinylphosphonates with perfect enantioselectivities was striking in these studies. In paper VI, we have reported the development of a new, highly enantioselective synthetic route to building blocks with CF3 at the chiral center. Several functionalized and unfunctionalized CF3-substituted olefins were hydrogenated with varied degree of success. This methedilogy is useful in the formation of chiral fluorine-containing molecules for a wide range of applications. Paper VII described the hydrogenation of imines using the phosphine-free Cp*Ru/diamine complexes. Chiral version of this reaction was also examined. Despite the modest results, this is the first study to use phosphine-free Cp*Ru/diamine complexes as catalysts for the reduction of C=N double bonds.