Abstract
The barbituric acid derivatives possess very interesting pharmaceutical properties and constitute an important group of nervous system depressants and sedative-hypnotics. One of these derivatives is 5,5-diethylbarbituratic acid (BA), which shows high hypnotic and sedative action. This work aimed to shed light on the complexation properties of the BA with several acceptors; quinol (QL), picric acid (PA), 1,3-dinitrobenzene (DNB) and tetrabromothiophene (TBT). All the prepared complexes were confirmed by UV–vis, IR spectrometry, and CHN elemental analysis. The 1:1 and 1:2 Benesi–Hildebrand equations were applied to estimate the spectroscopic data. Thermal decomposition behavior of complexes was studied, and their structural morphology was established by scanning electron microscope (SEM). Also, the thermodynamic parameters were calculated with Coats–Redfern and Horowitz–Metzger equations. Finally, the complexes were antimicrobial assessed against two kinds of bacteria and fungi species. The donation from BA to acceptors in decreasing order was found to be as follows: PA>DNB>QL>TBT. The complex containing the DNB acceptor exhibits a remarkable crystalline morphology. The complex containing the PA acceptor was found to be an efficient antifungal agent against Candida albicans.
The interesting morphology of [(BA)(DNB)] complex.
The complexation of BA with DNB leads to a highly well-defined microstructure in the nano-scale. This magnified SEM micrograph at a high magnification (×20 000) shows a smooth sheet-like-shaped morphology with a particle size of ~5μm. Such a microstructure offers large surface area. [Display omitted]
•Four new H-bonded complexes of 5,5-diethylbarbituratic acid were reported.•Complexes were characterized in both solution and solid state.•The complex containing the DNB acceptor exhibited a remarkable morphology feature.•The complex containing the PA acceptor possessed marked antifungal activity.