Spectroscopic characterization of the N'-(4-nitrophenylcarbonothioyl) nicotinohydrazide molecule has been studied using both experimental (X-ray diffraction and IR spectroscopy) and quantum mechanical methods. The tautomeric energetic analysis, structural optimization parameters (bond lengths and angles), vibrational wave numbers, UV-Vis. parameters, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) analyses and Molecular Electrostatic Potential (MEP) surface have been calculated by using DFT/B3LYP method with 6-311++G(2d,2p) level of theory to compare with the experimental results. The radical scavenging activity of the synthesized new compound has been evaluated using three different test methods. For this purpose, 2,2'-azino-bis-(3- ethylbenzothiazoline-6-sulfonate) (ABTS), N,N-dimethyl-p-phenylenediamine (DMPD) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity tests has been done. The pharmacokinetic, physicochemical, and toxicity properties have been defined by using drug-likeness and in silico ADMET studies. The interaction characterization with SARS-CoV-2 main protease (Mpro) of the title compound has been investigated via the help of a molecular docking study.