Theoretical investigation of 1,3-Di(n-pyridyl)-1,3-propanediones

The formation of the hydrogen bond stabilizes the chelated enol forms of β-diketones.Several experimental and theoretical data imply that some substituents in α- or β-positionssignificantly change the strength of intramolecular hydrogen bond (IHB) [1,2]. 1,3-Di(npyridyl)-1,3-propanediones (nPPD) can form polynuclear complexes due to existence the Nand O atoms at one side of these molecules. These compounds have the luminescentproperties and are expected to exhibit photostability [3]. The aim of the present study is toinvestigate the IHB strength (IHBs) of these compounds by means of DFT and AIMcalculations and comparing them with the corresponding values of similar compoundsAcetylacetone (AA), Dibenzoylmethane (DBM), and Hexafluoroacetylacetone (HFAA).