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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

ANÁLISE CONFORMACIONAL DO CIS E TRANS 2-HIDROXICICLOEXANOCARBOXILATO DE ETILA / Conformational analysis of cis and trans ethyl-2-hydroxycyclohexanecarboxylate

Negrelli, Mariana 25 February 2011 (has links)
Made available in DSpace on 2017-07-24T19:38:04Z (GMT). No. of bitstreams: 1 Mariana Negrelli.pdf: 2632259 bytes, checksum: 8ffb18e87e90aff84b82a1268dc4596f (MD5) Previous issue date: 2011-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work describes the conformational analysis of cis/trans ethyl-2 hydroxycyclohexanecarboxylate. For this, were analyzed data obtained by ab initio theoretical calculations, the nuclear magnetic resonance spectroscopy (coupling constants 3JHH) and infrared (carbonyl stretch). Were performed calculations for the isolated molecule and calculations with solvation routines to assess the conformational preference in different ways. With the aid of maps of electrostatic potential, was possible to observe the main negative centers where are located the reactive sites involved in organic synthesis. According to the calculations of NBO was analyzed how interactions affect the stability of each conformation. The compounds cis/trans ethyl-2-hydroxycyclohexanecarboxylate presented each, two preferred conformers, which were observed by both theoretical calculations and IR. The NMR spectroscopy was very useful because with the use of the same was possible to characterize the majority conformer of each equilibrium. / Neste trabalho é apresentado o estudo conformacional do cis/trans-2-hidroxicicloexanocarboxilato de etila. Para tanto, foram realizadas análises a partir de dados obtidos pelos cálculos teóricos ab initio e pelas espectroscopias de ressonância magnética nuclear (constantes de acoplamento 3JHH) e na região do infravermelho (estiramento da carbonila). Foram realizados cálculos para a molécula isolada bem como cálculos com rotinas de solvatação, para avaliar a preferência conformacional em diferentes meios. Com o auxílio de mapas de potencial eletrostático, foi possível observar os principais centros negativos onde estão localizados os sítios reativos envolvidos em sínteses orgânicas. Pelos cálculos de NBO, foi analisado como as interações afetam a estabilidade de cada conformação. Os compostos cis/trans-2-hidroxicicloexanocarboxilato de etila apresentaram cada um, dois confôrmeros preferenciais, os quais foram observados tanto pelos cálculos teóricos como por IV. A espectroscopia de RMN foi muito útil, pois com o emprego da mesma foi possível caracterizar o confôrmero majoritário de cada equilíbrio.

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