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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Síntese, reatividade e solvatacromismo de 1-azadienos obtidos via reação multicomponente de enaminonas

Nascimento, Melise Lemos 28 August 2015 (has links)
Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2016-05-02T14:42:08Z No. of bitstreams: 1 Dissertação_Melise1.pdf: 3394917 bytes, checksum: c73c2be1b42a99b78b32ccad002526eb (MD5) / Approved for entry into archive by Ana Hilda Fonseca (anahilda@ufba.br) on 2016-05-13T14:34:20Z (GMT) No. of bitstreams: 1 Dissertação_Melise1.pdf: 3394917 bytes, checksum: c73c2be1b42a99b78b32ccad002526eb (MD5) / Made available in DSpace on 2016-05-13T14:34:20Z (GMT). No. of bitstreams: 1 Dissertação_Melise1.pdf: 3394917 bytes, checksum: c73c2be1b42a99b78b32ccad002526eb (MD5) / CNPq, CAPES, FAPESB e INCT / O presente estudo traz reações regiosseletivas envolvendo enaminonas e sais de tetrafluorborato arenodiazônio como espécies eletrofílicas. Foram realizadas sínteses de enaminonas funcionalizadas, como as azoenaminonas, e compostos dela derivados. Dessa forma, ampliamos a quantidade de azocompostos derivados de enaminonas. As azoenaminonas são alcançadas via reação de acoplamento de sais de tetrafluorborato de arenodiazônio no carbono α-carbonílico de enaminonas, na presença de acetato de sódio. Baseando-se neste aspecto reacional, novas azoenaminonas foram sintetizadas, ampliaou-se o número de compostos azo e foram aperfeiçoados a síntese de seus derivados, os azadienos. No decorrer deste trabalho, foi possível racionalizar a síntese multicomponente para os 1-azadienos, provenientes da acetilação de azoenaminonas acíclicas derivadas da 4-amino-3-penten-2-ona. Foi proposta uma metodologia alternativa para a síntese tricomponente dos azadienos descritos na literatura. Nesta metodologia, que acontece “one-pot”, a enaminona acíclica sofre reação de acoplamento por sais de tetrafluorborato de arenodiazônio na presença do anidrido acético como solvente. Assim, foram testados diferentes sais de tetrafluorborato de arenodiazônio. Foram variados os padrões de substituição contidos no anel benzênico com a presença de grupos doadores, e/ou retiradores de elétrons. O grupo azo confere à molécula planaridade e permite que haja deslocamento de elétrons por sua estrutura, este aspecto peculiar possibilita que estes compostos apresentem atividade óptica não linear (ONL). A ONL pode ser mensurada utilizando cálculos teóricos semi-empíricos AM1. Uma vez apresentando potencialidade para ONL, o composto tende a apresentar propriedades que o tornam importantes, pois, podem ser utilizadas em tecnologias fotônicas. Dessa forma, a presença de grupos cromóforos tende a potencializar o efeito push-pull. Tal propriedade está diretamente relacionado com a hiperpolarizabilidade (β), propriedade que está diretamente relacionada a ONL. Com o intuito de contribuir com azocompostos análogos, realizou-se a síntese, caracterização e estudo solvatocrômico dos mesmos. O estudo solvatocrômico foi realizado obtendo-se espectros na região do ultravioleta-visível, identificando as principais bandas de absorção e tipos de transições eletrônicas envolvidas. Dessa forma, ampliação do escopo de novos azocompostos foi evidenciada, propondo uma nova metodologia de síntese de azadienos e um estudo solvatocrômico para os mesmos. / This report talks about regioselective reactions between enaminones and tetrafluorborate aryldiazone salts. Functionalized synthesis of enaminones, like azoenaminones, were developed and its derivatives compounds. The amount of azocompounds derivatives was amplified. The azoenaminones were obtained by coupling reactions of aryldiazone salt on the enaminone’s α- carbonyl carbon in the presence of sodium acetate. The sodium acetate, which contains on the reaction environment, neutralizes the tetrafluorboric acid from tetrafluorborate of aryldiazone that is produced by the reaction. Based on this reactional aspect, new azoenaminones were synthesized, the amount of azocompounds was amplified and also the syntheses of its derivatives– azodienes were improved. As the project was developed, was possible to rationalize the multicomponent synthesis to 1-azadienes from a reaction of acetylation of acyclic azoenaminones derivatives from 4- amine-3-penten-2-one. In addition to that an altenative methodology for the procedure described by the literature for tricomponent synthesis of azodienes was proposed. In that methodology which follows “one-pot reaction’s”, the acyclic enaminone pass through diazotization reaction starting from a reaction between aryldiazone salt and anidride acetic as a solvent. Then, different salts of aryldiazone tetrafluorborate were tested changing the substituition patterns that contains on the benzenic ring in the presence of electron donor groups and/or electron withdrawing groups. The azo group gives the molecule planarity and allows the movement of electrons happens because of its structure. This peculiar aspect allows this compounds to have optic non linear activity (ONL). The ONL might be measured by Photonic Technology. In the same way, the presence of chromophors groups tends to potencialize the effect “push-pull”. This characteristic is related to hiperpolarizability (β) which is straight related to ONL. In order to concur with analogues azocompounds, its synthesis, characterization and solvatochromic studies were developed. The solvatochromic studies were realized and the spectrums in gold-purple region were obtained and its absorption bands and eletronic transitions types involved were identified. Finally, the amplification of the scope of new azocompounds were reported and a new methodology of azodiene’s synthesis was proposed along to the solvatochromic study.

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