Resumo

GARCIA, Aída E. et al. Síntesis y evaluación fotocromática de compuestos espirobenzopiránicos. Rev. Soc. Quím. Méx [online]. 2004, vol.48, n.4, pp.269-274. ISSN 0583-7693.

The synthesis of 1', 3', 3'-trimethylspiro[2H-1]-benzopyran-2,2'-indoline derivatives with H, Br, I and NO₂ sustituents at the 6 and 8 positions of the benzopyran ring are reported. These compounds were obtained by condensation of 1,3,3-trimethyl-2-metilenindoline with 2-hydroxybenzaldehyde substituted in five position with several electrowithdrawing groups. The 6-nitro-spirobenzopyranindoline showed the best photochromatic activity. With the spectroscopic evaluation of this compound in the excited state it can be established that the absorption in the visible region of spectrum is independent of solvent polarity; however, the extent of stability of the colored form is greater by the increase of solvent polarity.

Palavras-chave : synthesis; spirobenzopyran; photochromic evaluation.

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