In this paper for the first time we report the results of molecular dynamics simulation of electrode/electrolyte interface of Li-O2 cathode under potential close to experimental values in 1M dimethyl sulfoxide (DMSO) solution of LiPF6 salt. Electric potential profiles, solvent structuring near the electrode surface and salt ions distributions are presented and discussed here as well as potentials of mean force (PMF) of oxygen and its reduction products. The latter would be of a great use for the future theoretical studies of reaction kinetics as PMF being essentially the work term is a required input for the reaction rate constant estimations. Electrode/electrolyte interface under the realistic potential effectively push oxygen anions out of the reaction layer that makes second reduction of superoxide anion hardly probable. Thus the main cause of the passivation should be the lithium superoxide presence near the electrode surface. The way to suppress the passivation is the shifting of equilibrium 2 − + + ⇌ 2 to the side of separately solvated ions, for example by using solvents resulting in lower free energy of the ions. This conclusion is in agreement with the hypothesis stating that high donor number solvents lead to dominantly solution Li2O2 growth and significantly higher cell discharge capacities.

The energy conversion efficiency of dye-sensitized solar cells derived from organic dye molecules has seen immense interest recently. In this work, we report a series of organic donor molecules with enhanced energy conversion efficiency using π-spacers and cyanoacrylic acid as an anchoring group (2−6). Density functional theory (DFT) and timedependent DFT calculations of these molecules have been performed to examine their electronic structures and absorption spectra before and after binding to the semiconductor titanium dioxide surface. The computational results suggest that dyes 4 and 6 have a larger driving force (ΔG inject = −1.66 and −1.80 eV, respectively) and light-harvesting efficiency (LHE = 0.99) in the series of donor molecules studied. Thus, these dyes should possess a larger short-circuit photocurrent density (J sc ) compared to the other examined dyes. The reported ΔG inject (−1.62 eV) and LHE (0.98) for compound 1, calculated with the same level of theory, were lower than those of the designed 4 and 6 dyes. Furthermore, the DFT calculations showed that the open-circuit photovoltage (V oc ) is improved with the vertical dipole moment and number of photoinjected electrons for 4 and 6. Dyes 4 and 6 are expected to exhibit high solar-energy-to-electricity conversion.

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SARS-COV-2, the novel coronavirus and root of global pandemic COVID-19 caused a severe health threat throughout the world. Lack of specific treatments raised an effort to find potential inhibitors for the viral proteins. The recently invented crystal structure of SARS-CoV-2 main protease (M pro) and its key role in viral replication; non-resemblance to any human protease makes it a perfect target for inhibitor research. This article reports a computer-aided drug design (CADD) approach for the screening of 118 compounds with 16 distinct heterocyclic moieties in comparison with 5 natural products and 7 repurposed drugs. Molecular docking analysis against M pro protein were performed finding isatin linked with a oxidiazoles (A2 and A4) derivatives to have the best docking scores of À11.22 kcal/ mol and À11.15 kcal/mol respectively. Structure-activity relationship studies showed a good comparison with a known active M pro inhibitor and repurposed drug ebselen with an IC 50 value of À0.67 lM. Molecular Dynamics (MD) simulations for 50 ns were performed for A2 and A4 supporting the stability of the two compounds within the binding pocket, largely at the S1, S2 and S4 domains with high binding energy suggesting their suitability as potential inhibitors of M pro for SARS-CoV-2.