A novel symmetrical mononuclear zinc complex: synthesis, crystal structure, Hirshfeld surface analysis, DFT calculations, and application in a supercapacitor electrode

International audienceThe development of supercapacitor electrodes based on metal complexes constitutes an interesting step toward different biomedical applications. In this context of research, a new Zn(DHA)2(DMSO)2 complex based on dehydroacetic acid (DHA) and dimethyl sulfoxide (DMSO) has been synthesized and structurally characterized. Suitable crystals for X-ray diffraction were collected by slow evaporation at room temperature. Single-crystal X-ray analysis revealed that the zinc ions bind through two carbonyl groups of the DHA ligand, and the titled complex is formed in a 1 : 2 metal–ligand stoichiometric ratio with an octahedral coordination geometry. Detailed Hirshfeld surface analysis and two-dimensional fingerprint plots were used to explore the intermolecular interactions in the material, and they revealed that the most significant contributions to the crystal packing are from H⋯H (45.5%), H⋯O/O⋯H (36.0%) and H⋯C/C⋯H (16.1%). In addition, using the DFT calculation method, the global descriptors are computed from the HOMO–LUMO orbitals, and the molecular reactivity sites are analyzed from an electrostatic potential map. Furthermore, an electrochemical study was carried out to estimate the energy storage capacity performance of the Zn(DHA)2(DMSO)2/graphene oxide (GO) hybrid material at a mass ratio of 100:1 which is sufficient for applications in many implantable health systems. The electrochemical results indicate that the Zn(DHA)2(DMSO)2/GO modified electrode exhibits excellent pseudo-capacitive behavior, with a specific capacitance of 36.40 F g−1 at 0.2 mA g−1 and a high specific energy (445 W h kg−1) at a high current (1 mA g−1). Excellent cycling stability with a specific capacitance retention of 105% after 2000 charge–discharge cycles at 10 mA g−1 was also observed. In summary, the Zn(DHA)2(DMSO)2/GO modified electrode can be explored as a supercapacitor electrode that can be applied in energy storage devices for biomedical electronics dedicated to health monitoring

Crystal structure, Hirshfeld surface and reactivity of novel ligand-L-AT1 derived from dehydroacetic acid: intermolecular interactions with SARS-Cov-2/main protease

International audienceThe crystals of new ligand, namely (3E)-6-methyl-3-{1-[(pyridin-3-ylmethyl) amino] ethylene}-2H-pyran-2, 4(3H)-dione) (L-AT1), were synthesized using the evaporation solution technique. Single-crystal X-ray diffraction and physico-chemical characterization (ATR, proton and carbon-13 NMR and UV-Visible) of L-AT1 were reported. In addition, Hirshfeld surface analysis (HSA) of the solid compound, structure optimization, Mulliken and NBO charges, global indices of reactivity, local reactivity descriptors and molecular electrostatic potential (MEP) of the ligand were investigated theoretically. XRD analysis showed that L-AT1 crystallizes in the triclinic space group P-1 and the structure was stabilized through hydrogen bonds. HAS revealed that H horizontal ellipsis H (46.5%) and O horizontal ellipsis H (25.7%) contacts are in control of crystal stacking. The energy gap (4.679 eV) and reactivity descriptors indicate the stability of L-AT1. The Mulliken and NBO charges showed that the protons have a positive charge and the heteroatoms exhibit negative charges. The Fukui function and MEP study revealed that the heteroatoms are the most reactive sites for an electophilic attack on the ligand. Molecular docking simulation shows that the significant binding affinity of L-AT1 with SARS-CoV-2/Mpro is due to the formation of high number of hydrogen bonds