Abstract
The electronic and spatial structures of newly synthesized derivatives of β-diketones were studied based on the results of quantum chemical calculations. The properties of β-diketones with substituted phenyldiazonium chloride, namely 8 tautomers aryl derivatives of β-diketones-(E)-3-(2-(1-(dimethylamino)-1,3-dioxobutan-2-ylidene)hydrazinyl)-2-hydroxy-5-nitrobenzene sulfonic acid (H3L1) have been studied using the PM3 semi-empirical quantum chemistry method and the density functional theory (DFT) method with the B3LYP hybrid functional and 6-31+G(d,p) basis set. Energy and electronic characteristics of 8 tautomers are investigated. The effect of intramolecular hydrogen bonding on the structure of the investigated compounds has been studied. The formation of hydrogen bonds was confirmed by Natural Bond Orbital (NBO) analysis. Theoretical studies using the PM3 and DFT methods confirm the practical conclusions about the superiority of the hydrazone form in real samples.