Molecular design of new π-conjugated materials based on pyrimidine for organic solar cellsapplication

The research in new π-conjugated molecules with specific applications has become one of the most interesting topics in the fields of chemical physics and materials science.In fact, these compounds have been widely explored, thanks to their essential particular properties, as novel class of promising materials in the field of optoelectronics. In this work, we emphasize the importance of the materials based on pyrimidine π- conjugated derivatives due to their strong potential for solar cell applications. The Density Functional Theory (DFT) approach at B3LYP level and 6-31G(d,p) orbital basis sets for all atoms as implemented in Gaussian 09 program has been used for complete geometry optimization with no constraints of pyrimidine π-conjugated based derivatives.The assessed molecular properties comprise the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and other molecular properties derived from HOMO and LUMO and their respective energies. The absorption spectra were simulated by Time-Dependent Density Functional Theory (TD/DFT) at the B3LYP/6-31G(d,p) level owing to the calculation of the oscillator strengths, the maximum absorption wavelengths and the excitation energy corresponding to the pyrimidine π-conjugated derivatives. The open circuit voltage and the difference between both the LUMO energy levels of the donor and the acceptor have been also evaluated. Hence, we have scanned the rapport, for the molecules under study, between the molecular, the electronic structure and the efficiency of the solar cell in order to give further insights on the possibility of electron transfer between the donor and the acceptor entities. Our results lead to the likelihood to suggest pyrimidine based materials as bulkheterojunction solar cell for organic solar cells application.

Experimental study of the corrosion inhibition of mild steel by the N1, N1, N5, N5-tetrakis ((1H-pyrazol-1-yl) methyl) naphthalene-1,5-diamine in hydrochloric acid solution

Nitrogen-containing heterocyclic organic compounds have been found to be effective in corrosion inhibitors, especially in hydrochloric acid media. The purpose of this study is to investigate the inhibition performance of N1, N1, N5, N5-tetrakis ((1H-pyrazol-1-yl) methyl) naphthalene-1, 5-diamine (NPD) on mild steel in 1 M HCl solution. The inhibitive action of this compound against the corrosion of mild steel in 1 M HCl solution has been investigated using weight loss measurements, Tafel Polarization and electrochemical impedance spectroscopy (EIS) techniques. The results obtained from the different corrosion evaluation techniques are in good agreement. Results obtained reveal that this compound performs excellently as corrosion inhibitor for mild steel in HCl 1M solution. The temperature effect on the corrosion behavior of mild steel in 1 M HCl with and without product at different concentrations was studied in the temperature range from 313 to 343 K. The adsorption free energy and activation parameters for the mild steel dissolution reaction were determined. Adsorption of this inhibitor on the mild steel surface in 1M HCl follows the Langmuir isotherm model. The surface characteristics of inhibited and uninhibited mild steel were investigated by scanning electron microscopy (SEM) and EDX studies. Quantum chemical approach, using the density functional theory (DFT)at B3LYP/6-31G (d,p) level, was realized in order to explain the inhibitory action and to get a better understanding about the relationship between the inhibition efficiency and molecular structure of NPD and the calculated quantum chemical parameters were discussed. The theoretical results were found to be consistent with the experimental data.  

ROSEMARY ESSENTIAL OILS: EXTRACTION, GC/MS ANALYSIS, ANTIOXIDANT ACTIVITY WITH DFT AND IN SILICO INSIGHTS OF PROSPECTIVE NANO-ANTIOXIDANTS

The objective of this work is to identify the bioactive molecules in the essential oil of the dried leaves of Rosemary from two cities in the Eastern region of Morocco: Taourirt and Jerrada. These essential oils have already been extracted by the steam distillation method in the cooperative. the chemical composition have been determined by gas chromatography coupled with mass spectrometry (GC/MS), in which cineole 41.77%, alpha-Pinene 10.75% and Camphor 9.32% represent the majority compounds for essential oil of Rosemary from Taourirt and cineole 51.68%, alpha-Pinene 11.91 % and Camphor 10.29 % predominate in that of Jerada rosemary. Antioxidant activity in vitro was assessed in three different ways: the DPPH test, the β-carotene bleaching technique, and the reduction power measurement. The DFT analysis of the different compounds and the Docking study were also investigated in objective to study the molecular reactivity of the majority compounds, also study their affinity to various cyclodextrin as prospective encapsulation systems

Inhibition Effect of 6-bromo-3-nitro-2-phenylimidazol[1,2-α] pyridine on the Corrosion of C38 Steel in H2SO4 Solution

The inhibition effect of 6-bromo-3-nitro-2-phenylimidazol[1,2-α] pyridine (BNPP) on the corrosion of C38 steel in 0.5 M H2SO4 was studied by weight loss , electrochemical methods. The results showed that BNPP was a good inhibitor in 0.5 M H2SO4 and this adsorption obeyed the Langmuir adsorption isotherm. The results obtained from the different corrosion evaluation techniques are in good agreement. Polarization curves showed that BNPP acted as a mixed-type inhibitor in sulfuric acid. The effect of the temperature on the corrosion behavior with addition of 10-3M of the inhibitor was studied in the temperature range 298-328 K, and the thermodynamic parameters were determined and discussed. Quantum chemical approach, using the density functional theory (DFT), was applied in order to get better understanding about the relationship between the inhibition efficiency and molecular structure of BNPP. The theoretical results were found to be consistent with the experimental data

Centralised Design and Production of the Ultra-High Vacuum and Laser-Stabilisation Systems for the AION Ultra-Cold Strontium Laboratories

This paper outlines the centralised design and production of the Ultra-High-Vacuum sidearm and Laser-Stabilisation systems for the AION Ultra-Cold Strontium Laboratories. Commissioning data on the residual gas and steady-state pressures in the sidearm chambers, on magnetic field quality, on laser stabilisation, and on the loading rate for the 3D Magneto-Optical Trap are presented. Streamlining the design and production of the sidearm and laser stabilisation systems enabled the AION Collaboration to build and equip in parallel five state-of-the-art Ultra-Cold Strontium Laboratories within 24 months by leveraging key expertise in the collaboration. This approach could serve as a model for the development and construction of other cold atom experiments, such as atomic clock experiments and neutral atom quantum computing systems, by establishing dedicated design and production units at national laboratories.Comment: 27 pages, 21 figure