A nickel(II) complex with an unsymmetrical tetra-dentate chelating ligand derived from pyridine-2,6-dicarbaldehyde and 2-amino-thio-phenol.

[(2-{[6-(1,3-Benzo-thia-zol-2-yl)pyridin-2-yl]carbonyl-aza-nid-yl}phen-yl)sulf-anido]nickel(II), [Ni(C19H11N3OS2)], crystallizes in the centrosymmetric monoclinic space group P21/n with one mol-ecule in the asymmetric unit. The expected ligand, a bis-Schiff base derived from pyridine-2,6-dicarbaldehyde and 2-amino-thio-phenol, had modified in situ in a both unexpected and unsymmetrical fashion. One arm had cyclized to form a benzo[d]thia-zol-2-yl functionality, while the imine linkage of the second arm had oxidized to an amide group. The geometry about the central NiII atom is distorted square-planar N3S. The mol-ecules form supra-molecular face-to-face dimers via rather strong π-π stacking inter-actions, with these dimers then linked into chains via pairwise C-H⋯O inter-actions.

Synthesis and investigation of anti-COVID19 ability of ferrocene Schiff base derivatives by quantum chemical and molecular docking.

The recent outbreak of coronavirus disease (COVID-19) has rampaged the world with more than 236 million confirmed cases and over 4.8 million deaths across the world reported by the world health organization (WHO) till Oct 5, 2021. Due to the advent of different variants of coronavirus, there is an urgent need to identify effective drugs and vaccines to combat rapidly spreading virus varieties across the globe. Ferrocene derivatives have attained immense interest as anticancer, antifungal, antibacterial, and antiparasitic drug candidates. However, the ability of ferrocene as anti-COVID-19 is not yet explored. Therefore, in the present work, we have synthesized four new ferrocene Schiff bases (L1-L4) to understand the active sites and biological activity of ferrocene derivatives by employing various molecular descriptors, frontier molecular orbitals (FMO), electron affinity, ionization potential, and molecular electrostatic potential (MEP). A theoretical insight on synthesized ferrocene Schiff bases was accomplished by molecular docking, frontier molecular orbitals energies, active sites, and molecular descriptors which were further compared with drugs being currently used against COVID-19, i.e., dexamethasone, hydroxychloroquine, favipiravir (FPV), and remdesivir (RDV). Moreover, through the molecular docking approach, we recorded the inhibitions of ferrocene derivatives on core protease (6LU7) protein of SARS-CoV-2 and the effect of substituents on the anti-COVID activity of these synthesized compounds. The computational outcome indicated that L1 has a powerful 6LU7 inhibition of SARS-CoV-2 compared to the currently used drugs. These results could be helpful to design new ferrocene compounds and explore their potential application in the prevention and treatment of SARS-CoV-2.

Synthesis, Characterization, Electrochemistry, Photoluminescence and Magnetic Properties of a Dinuclear Erbium(III)-Containing Monolacunary Dawson-Type Tungstophosphate: [{Er(H2O)(CH3COO)(P2W17O61)}2]16.

Reaction of the trilacunary Wells-Dawson anion {α-P2W15O56}12- with ErIII ion in a 1 M LiOAc/HOAc buffer (pH 4.8) solution produces a dinuclear erbium(III) substituted sandwich-type structure [{Er(H2O)(CH3COO)(P2W17O61)}2]16- (1). The isolated compound was structurally characterized using single crystal and powder X-ray diffraction, FTIR spectroscopy, mass spectrometry and thermogravimetric analysis. The electrochemical, electrocatalytic, photoluminescence and magnetic properties of 1 were investigated.