Synthesis and structural study of azo-enaminones. / Síntese e estudo estrutural de azo-enaminonas.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Azoenaminones are a particular class of enaminones obtained by incorporation of azo group (N=N), on into a conjugated system N-C=C-C=O of enaminone moiety. Studies concerning of this class of organic compounds are still scarce this and of their properties and reactional behavior. Nowadays there are a few numbers this and of compounds synthesized, but the recent studies highlight its potential applications. Preliminary studies indicate that these compounds have a complex isomeric behavior, coexisting as geometric isomers and showing hydrazoimino/azoenamine tautomerism in one of the geometric form. Based on experimental data and also in computational methods, these compounds are potential candidates to be applied in second-order nonlinear optical (NLO) for second harmonic generation (SHG). This fact is attributed to the extensive of conjugated p-electron chain, that is present in the enaminone moiety, intensified by the presence of the azo group, increased by action of the electronic releasing amino group and by the receptor group (NO2, Cl) originated by the azo compound, that increment the push-pull effect of electrons, and the potential NLO activity of the molecule. In this work, it was synthesized the azoenaminones 4-amino-3-(4-nitro-phenyldiazenyl)pent-3-en-2-one (4a), 4-amino-3-(4-chloro-phenyldiazenyl)pent-3-en-2-one (4c) and three new azoenaminones, 4-amino-3-(2-chloro-phenyldiazenyl)pent-3-en-2-one (4b), 4-cyclo-hexylamino-3-(4-nitro-phenyldiazenyl)pent-3-en-2-one (4b) and the 4-[ ethyl 1-S-methyl-etanoate)-amino-3-(4-nitro-phenyldiazenyl)pent-3-en-2-ona(4e). As the experimental method for the indirect measure of NLO activity of these compounds, it was used the solvatochromic study that analyze the influence of chromophos groups along the molecular. The electrochemical activity was also explored. Thus, it was abtained the redox potential of these compounds. This potencial is related with the intramolecular delocation of the p-electron efficiency, as parameter for estimate the optical properties of these compounds. Additionally, the crystalline structure of 4a, 4b and 4e was identified by X-ray diffraction, being that the azoenaminone 4a, 4b and predominates in the azo form and 4e in the hydrazoimino form.

ASSUNTO(S)

diazonium salts tautomerismo sais de diazônio toutomerism azo-enaminones azo-enaminonas quimica organica

ACESSO AO ARTIGO

Documentos Relacionados