M Vakili - Department of Chemistry, Ferdowsi University of Mashhad, Mashhad 91775-1436, Iran
R Afzali - Department of Chemistry, Ferdowsi University of Mashhad, Mashhad 91775-1436, Iran
M Hakimi-Tabar - Department of Chemistry, Ferdowsi University of Mashhad, Mashhad 91775-1436, Iran

The cis-enol form of β-diketones is characterized by a strong intramolecular hydrogenbond [1,2]. The formation of the hydrogen bond causes an increase in resonance conjugationthrough the resulting six-member chelating ring. So, any parameter that affects the electrondensity of the chelating ring will alter the hydrogen bond strength [3,4]. The aim of thepresent study is investigating of the substitutions on hydrogen bond strength in some α-cyano-1,3–diketones by means of DFT, AIM and NBO methods. The mentioned compoundscompared to each other due to better understanding of substitutions effect.