Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro de Ciencias Fisicas e Matematicas / Made available in DSpace on 2012-10-16T04:45:23Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-08T16:59:37Z : No. of bitstreams: 1 88560.pdf: 2490300 bytes, checksum: 8651878e0dfcd6e802a75770c6697839 (MD5) / Neste trabalho foi realizado o estudo cinético das reações de solvólise de tosilatos de 1-aril-2,2,2-trialogenoetila em diversos solventes e misturas de solventes (metanol-água 60, 80 e 90%, etanol 100%, etanol-água 80 e 90%, trifluoroetanol 100% e hexafluoroisopropanol 100%). Estudou-se também o comportamento cinético das reações de solvólise dos tosilatos de 1-(4-metoxifenil)-2,2,2-tribromoetila em soluções metanólicas contendo percloratos de metais alcalinos e alcalino-terrosos em concentrações crescentes de 0 a 2 M.

A series of ferrocenylimine [(£b5-C5H5)Fe(£b5-C5H4-C(Me)=N-R)]¡AR= nhexyl(1a)¡Acyclohexyl(1b)¡Aphenyl(1c)¡AN,N-dimethylethylamino(1d) ¡A4-methoxyphenyl(1e)¡A4-nitrophenyl(1f)¡Aand 2-methoxyethyl(1g)¡Ahave been synthesized by reaction of acetylferrocene and the corresponding amines through condensation reaction. Also 1,1¡¦-ferrocenyldiimines [Fe{(£b5-C5H4)-C(Me)=N-R}2]¡AR= nhexyl(2a)¡Acyclohexyl(2b)¡Aphenyl(2c)¡AN,N-dimethylethylamino(2d)¡A4-methoxyphenyl(2e)¡A4-nitrophenyl(2f)¡A3-nitrophenyl(2g)¡A2-methoxyethyl(2h) have been synthesized by reaction of 1,1¡¦-diacetylferoocene and the corresponding amines through condensation reaction. Solid state crystal X-ray structural analysis revealed the geometry of the ferrocene derivatives are various with the different substituents . In addition, these ferrocene derivatives might coordinate with CuBr to form a series of iminoferrcenyl copper(¢¹) complexes. Solid state crystal X-ray structural analysis revealed the iminoferrcenyl copper(¢¹) complexes 3a~3d showed monomeric or dimeric geometry and diiminoferrcenyl copper(¢¹) complexes 4a~4d exhibited polymeric or dimeric geometry. All synthesized ferrocenylimine and1,1¡¦-ferrocenyldiimines derivatives exhibited a reversible one ¡Velectron redox process in their cyclic voltammograms, and the values of their redox potentials relied on the R groups. The correlation between the redox potential and the Hammett substituent constant, £mp was quite well, with a correlation coefficient of 0.96 in CH2Cl2 and CH3CN. According to the cyclic voltammograms, iminoferrocenyl copper complexes showed that the substituents on the imino parts strongly affect the redox potentials of the iron centers in the ferrocenyl segments as well as the copper metal center. The Cu+/Cu2+ couple redox potentials are in the range of 0.269V and 0.719V dependent on solvent effect. The iminoferrocenyl copper complexes¡¦s UV-vis absorption seems to be red shift comparing with iminoferrocene. In the CH2Cl2, compound 3a¡B3b¡B4d shows emission at £fmax ~ 408 nm . In the CH3CN, compound 3a¡B3b¡B3c¡B3d¡B4a¡B4b and 4c show the blue shift emission band comparing with iminoferrocenyl copper complexes in CH2Cl2. In addition, complex 4d in CH2Cl2 and complex complex 3d in CH3CN showed higher quantum yield value. Moreover, compound 1a and 2a combined with CuBr exhibit good catalytic activity and controlling ability in the MMA ATRP process.

No / Competition experiments in which 1,2-phenylenediamine, C6H4(NH2)2, condenses with equimolar quantities of benzil, (C6H5CO)2, and a 3,3'- or 4,4'-disubstituted benzil (XC6H4CO)2 (X = F, Cl, Br, CH3 or CH3O) to form a mixture of 2,3-diphenylquinoxaline and the corresponding 2,3-diarylquinoxaline (Ar = XC6H4) in the microdroplets produced in a nebuliser allow a Hammett relationship with a ρ value of 1.85 to be developed for this accelerated condensation in the nebuliser. This structure reactivity relationship reveals that an appreciable amount of negative charge builds up on the carbon of the carbonyl group of the benzil during the rate-limiting step of the reaction, thus confirming that this process involves nucleophilic addition of the 1,2-phenylenediamine to the benzil. In general, the presence of an electron donating substituent, particularly in the 4 and 4' positions, in the benzil retards the reaction, whereas an electron attracting substituent, especially in the 3 and 3' position, accelerates it. / 2019 British Mass Spectrometry Summer Studentship for NWF.

Não consta resumo na publicação. / Abstract not available.

Não consta resumo na publicação. / Abstracts nor available.

Orientador: Yuji Takahata / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-05T10:46:03Z (GMT). No. of bitstreams: 1 Segala_Maximiliano_D.pdf: 2643298 bytes, checksum: 90403c336f5d4adb79c5c766cea52068 (MD5) Previous issue date: 2005 / Doutorado / Físico-Química / Doutor em Ciências

Não consta resumo na publicação. / Abstract not available.

Não consta resumo na publicação. / Abstracts nor available.

Les microsystèmes sont des réacteurs extraordinaires pour mettre en œuvre des réactions chimiques car ils apportent un rapport de contact entre phases très supérieur à celui en ballon, la possibilité d’hypertrempe thermique tant au chauffage qu’au refroidissement et enfin l’absence d’interaction des réactifs avec les produits. Les dimensions micro-ou nanométriques de ces réacteurs sont très largement compensées par la possibilité de parallélisation à grande échelle de ces réacteurs qui permet une montée en échelle de la production sans nouveau développement. Nous avons choisi comme réaction test l’alkylation des acides benzoïques substitués par l’iodure de méthyle en présence d’une éponge à proton (TMGN). Cette réaction a été choisie car elle suit une cinétique parfaitement du second ordre. Nous avons ainsi pu montrer que cette réaction suit la relation de Hammett, déterminer le paramètres de réactivité  pour cette réaction et en opérant à température variable mesurer l’énergie et l’entropie d’activation. Nous avons également réalisé des expériences préparatives sur des substrats bifonctionnels simples et mis en évidence la sélectivité en système microfluidique. Une étude comparative de la basicité des superbases organiques comparée à la vitesse d’alkylation par l’iodure de méthyle a effectué pour mieux cerner le rapport basicité, nucléophilie de ces bases qui est peu étudié. Parallèlement l’alkylation d’un polyphénol complexe la quercétine et de substrats à haute valeur ajoutée tels que le Trolox, l’acide clofibrique et l’acide podocarpique à l’aide de systémes microfluidiques ont été étudié à l’échelle de la millimole. / Microfluidic devices have extensively been used in chemical synthesis, due to providing high surface area between phases, ease of heating or cooling and the absence of interaction between products and reactants. Microreactors can be used in parallel for scale-up purposes without any additional designing step. Here, we have studied the alkylation of substituted benzoic acids by iodomethane at the presence of a proton sponge (TMGN). This reaction was chosen because it follows second-order kinetics. The Hammett reaction constant was obtained for this reaction and by studying the reaction kinetics in different temperatures, the activation parameters were obtained. Using this set-up and using bi-functional substrates the reaction selectivity in microsystem was also investigated. By this microreactor kinetics of N-alkylation of several organic superbases by iodomethane was also studied. Finally, the microreactor system enabled small scale synthesis of several natural compounds. The alkylation of quercetin, Trolox, clofibrique acid and podocarpic acid by iodomethane at the presence of TMGN was conducted at the scale of millimole.

Texte remanié de: Dissertation--Kassel, 2004.