Synthesis, DFT, Spectroscopic Studies and Electronic Properties of Novel Arginine Derivatives

In this work, four derivatives of arginine with biologically active acids: acetylsalicylic, butyric, nicotinic, and succinic acids were obtained and characterized using UV-visible, IR, 1 H NMR, and 13 C NMR spectroscopy. In addition to spectroscopic analyses, DFT calculations were applied to predict the physicochemical properties of the studied compounds. The IR and NMR parameters were evaluated and compared with those experimental results obtained in the spectra. Moreover, the electronic transitions in the UV-Vis region of the electromagnetic spectrum were studied through the visualization of FMOs as well a calculation of energy gap values and TD-DFT calculations. It was found that the compounds maximally absorb the electromagnetic radiation at a wavelength range of 156.78–181.54 nm which can be due to π–π* and n –π* electronic transitions. Finally, QTAIM topological analysis showed that inter-molecular hydrogen bonds have a key role in the formation of arginine derivatives.