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| Format: | Artículo científico |
| Language: | es |
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Universidad San Francisco de Quito
2010
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| Online Access: | https://www.redalyc.org/articulo.oa?id=726180822004 |
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Table of Contents:
- Síntesis de 2,8,14,20-tetra-n-butilpirogalol[4]areno y estudio computacional conformacional Cesar H. Zambrano Carlos A. Manzano Andrea A. Saltos Eric E. Dueno Matthew Zeller Multidisciplinaria (Ciencias Naturales y Exactas) ray butyl conformation Pyrogallolarene semiempirical calculations The macrocycle 2,8,14,20-tetra-n-butilpirogalol[4]areno was syntesized by acid catalized condensation of pyrogallol and butanal. The product was isolated by recrystallization from an acetone-water mixture which yielded single crystals suitable for an X-ray diffraction study. The latter revealed a P-1, triclinic unit cell of dimensions a=11.63920(10) Å, b=12.8367(2) Å, c=17.5423(2) Å and α=104.1070(10)o β=95.6630(10)o γ=101.5790(10)o , which contained two molecules of the tetramer related to each other by an inversion center. The solid state structure of the macrocycle shows an all cis- conformation (rccc), also called crown or cone structure, which is consistent with all other known aliphatic derivatives of pyrogallolarenes. A semiempirical computational calculation (AM1 and PM3) was carried out on the aforementioned compound to determine if the observed conformation was more stable than the chair (rctt) structure. These calculations were also performed on other reported derivatives of pyrogalloloarenes with aliphatic and also with aromatic substituents. The results indicated that for all pyrogallol[4]arenes the most stable (thermodynamic) conformation is the rccc; which suggest that the chair structure observed for aromatic derivatives may be a kinetic product. 2010 artículo científico 1390-5384 https://www.redalyc.org/articulo.oa?id=726180822004 es http://www.redalyc.org/revista.oa?id=7261 Avances en Ciencias e Ingenierías application/pdf Universidad San Francisco de Quito Avances en Ciencias e Ingenierías (Ecuador) Num.2 Vol.2