The open chain β-dicarbonyl compounds are in the cis-enol and keto forms. Several factors are involved in determination of tautomerization equilibrium position, such as nature of α- and β-substituted groups, polarity of solvent, and temperature [1]. 2-Bromo-1,3-diphenylpropane-1,3-dione (BrDBM), α-Bromo- benzoylacetone (BrBA), and α-Bromo-acetylacetone (BrAA) could be interesting candidates for study of keto-enol tautomerization. since existing of one and two phenyl groups in the β-positions highly increases the enol content whereas substitution of Br in the α-position decreases the enol content. So the noteworthy aim in ongoing research is to crosscheck the effects of different α or β-substitutions on the enol content and intramolecular hydrogen bonding (IHB) strength of the mentioned molecules. The tautomerism, geometry, IHB strength, vibrational and 1HNMR spectroscopy of the mentioned molecules, which are in the keto and/or enol forms, have been investigated by theoretical and experimental (X-ray and spectroscopic) methods. The mentioned results were compared together, excellent agreement was observed between them [2-3]. The open chain β-dicarbonyl compounds are in the cis-enol and keto forms. Several factors are involved in determination of tautomerization equilibrium position, such as nature of α- and β-substituted groups, polarity of solvent, and temperature [1]. 2-Bromo-1,3-diphenylpropane-1,3-dione (BrDBM), α-Bromo- benzoylacetone (BrBA), and α-Bromo-acetylacetone (BrAA) could be interesting candidates for study of keto-enol tautomerization. since existing of one and two phenyl groups in the β-positions highly increases the enol content whereas substitution of Br in the α-position decreases the enol content. So the noteworthy aim in ongoing research is to crosscheck the effects of different α or β-substitutions on the enol content and intramolecular hydrogen bonding (IHB) strength of the mentioned molecules. The tautomerism, geometry, IHB strength, vibrational and 1HNMR spectroscopy of the mentioned molecules, which are in the keto and/or enol forms, have been investigated by theoretical and experimental (X-ray and spectroscopic) methods. The mentioned results were compared together, excellent agreement was observed between them [2-3].

Keywords