Complementary hydrogen bonding of a carboxylato-barbiturate with urea and acetamide: Experimental and theoretical approach

A barbiturate derivative, 4-(2,4,6-trioxo-tetrahydro-pyrimidine-5-ylidenemethyl)-benzoic acid (L1) possessing functional complementarity to amides has been synthesized and characterized. Its binding separately with urea and acetamide was monitored using UV–vis, fluorescence and 1H-NMR spectroscopic titrations. Experiments suggested stronger binding of L1 with urea as compared to acetamide. The solid adducts of L1 prepared separately with urea and acetamide were also characterized using IR, 1H-NMR spectral and PXRD techniques. Theoretical studies on hydrogen bonded complexes of L1–urea and L1–acetamide in the gas phase, aqueous, and DMSO medium were carried out using density functional theory (DFT) at the B3LYP/6-31G** level. The theoretical calculations agreed to the experimental results.

Graphical abstractThe binding of urea and acetamide with a barbiturate derivative 4-(2,4,6-trioxo-tetrahydro-pyrimidine-5-ylidenemethyl) benzoic acid (L1) possessing functional complementarity with them, is monitored using UV–vis, fluorescence and 1H-NMR spectroscopic titrations and DFT calculations which agreed to the experimental results.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A carboxylato-barbiturate (L1) shows functional complementarity to urea and acetamide. ► Its binding property is monitored using UV–vis, fluorescence and 1H-NMR spectroscopic techniques. ► The experimental results are supported by DFT calculations.