Silesian University of Technology, Faculty of Chemistry, Krzywoustego 4, 44-100 Gliwice, Poland.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Oct;96:815-9. doi: 10.1016/j.saa.2012.07.109. Epub 2012 Aug 4.
UV absorption spectra of dibenzoylmethane and its 23 derivatives with acetamide, tert-butyl, chloride, fluoride, hydroxyl, methyl, methoxy and nitro substituents in aromatic rings were collected. General influence of substituent on absorption maxima and absorption intensity was defined. Hyperchromic effects were observed for diketones with electron-donating groups in para postion. The keto-enol tautomerism equilibrium constant of obtained compounds was investigated with (1)H NMR spectroscopy. Significant changes of equilibrium were observed only for ortho substituted compounds. Results revealed dissimilarity of substituent effects on absorption and keto-enol tautomerism of aromatic β-diketones.
收集了二苯甲酰甲烷及其 23 种带有乙酰基、叔丁基、氯、氟、羟基、甲基、甲氧基和硝基取代基的衍生物在芳香环中的紫外吸收光谱。定义了取代基对吸收最大值和吸收强度的一般影响。具有供电子基团的二酮在对位时表现出增色效应。用 (1)H NMR 光谱法研究了所得化合物的酮-烯醇互变异构平衡常数。仅对于邻位取代的化合物观察到平衡的显著变化。结果表明，取代基对芳香族β-二酮的吸收和酮-烯醇互变异构的影响不同。
