کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1412008 | 1501926 | 2006 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Phase transition and intramolecular hydrogen bonding in nitro derivatives of ortho-hydroxy acetophenones Phase transition and intramolecular hydrogen bonding in nitro derivatives of ortho-hydroxy acetophenones](/preview/png/1412008.png)
The crystal structures of two ortho-hydroxy aryl ketones (5-chloro-3-nitro-2-hydroxyacetophenone, 5-methyl-3-nitro-2-hydroxyacetophenone and the complex 5-chloro-3-nitro-2-hydroxyacetophenone with 2-aminobenzoic acid (anthranilic acid)) were determined by X-ray diffraction. The existence of an intramolecular hydrogen bond of enol character between the hydroxyl and acetyl groups was found by the X-ray method. The enol character was also confirmed by DFT (B3LYP/6-31+G(d,p)) calculations. A phase transition was found at 138 K in 5-chloro-3-nitro-2-hydroxyacetophenone. This phase transition was investigated by differential scanning calorimetry (DSC), dilatometry, and the dielectric method. A study of the nitro-group dynamics in the ortho-hydroxy acetophenones was carried out with DFT (B3LYP/6-31+G(d,p)) calculations.
Journal: Journal of Molecular Structure - Volume 785, Issues 1–3, 6 March 2006, Pages 7–13