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The chemical imidacloprid belongs to the neonicotinoids insecticide class, widely used for insect pest control mainly for crop protection. However, imidacloprid is a non-selective agrochemical to the insects and it is able to kill the most important pollinators, the bees. The high toxicity of imidacloprid requires controlled release and continuous monitoring. For this purpose, high performance liquid chromatography (HPLC) is usually employed; infrared and Raman spectroscopy, however, are simple and viable techniques that can be adapted to portable devices for field application. In this communication, state-of-the-art quantum level simulations were used to predict the infrared and Raman spectra of the most stable conformer of imidacloprid. Four molecular geometries were investigated in vacuum and solvated within the Density Functional Theory (DFT) approach employing the hybrid meta functional M06-2X and the hybrid functional B3LYP. The M062X/PCM model proved to be the best to predict structural features, while the values of harmonic vibrational frequencies were predicted more accurately using the B3LYP functional. [ABSTRACT FROM AUTHOR]

• Strucures of lignin models. • Relationship between βO4 bond and structure of lignin. • Use of density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) in the βO4 bond. • Analysis of non-covalent interactions (NCI) for βO4 bond. Lignin is a natural macromolecule that, in general, is formed by the aromatic units S, G and H depending on its origin. From its structure it is possible to obtain molecules with high added value, however the processes face difficulties in the need to break the bond that unites these aromatic units, the βO4 bond. This work, through computational models via DFT, QTAIM and NCI, investigated the main intramolecular interactions and their properties related to this bond. It was possible to observe that lignins with methoxyl linked to the second aromatic unit (SAU) perform interactions that are totally different from models that do not have them. For some specific conformations, hydrogen bonds between the gamma hydroxyl and the SAU methoxyl were characterized and it was found that these are responsible for making the βO4 bond stronger. However, the methoxylated models are dominated by repulsive and destabilizing interactions that make their βO4 bonds, in general, 4.41% weaker than the models formed by H units, which perform attractive and stabilizing dihydrogen interactions. [Display omitted] [ABSTRACT FROM AUTHOR]

• The electrodeposition of antimony is studied in 1ChCl:2EG with water addition. • Sb films were successfully electrodeposited in the 1ChCl:2EG. • Water addition enhances Sb electrodeposition in choline chloride-ethylene glycol. • The addition of water influences on morphology and composition of Sb films. • The increased number of H 2 O molecules in all systems increases the electronic affinity. • The addition of H 2 O molecules decreases the electronic density of Sb3+ ions BCPs in all systems. Through experimental research and theoretical calculation, it was investigated the effect of water and temperature on the electrodeposition of antimony (Sb) on a platinum (Pt) electrode. The plating solutions were prepared by the addition of 0.05 mol L–1 SbCl 3 to the mixtures of choline chloride (ChCl), ethylene glycol (EG) and water (W) in the following molar ratio: 1ChCl:2EG (bath 1), 1ChCl:2EG:0.45 W (bath 2), and 1ChCl:2EG:1.62 W (bath 3). Furthermore, the Sb coatings were electrodeposited at 297 and 338 K. The surface morphologies and crystalline structures of Sb electrodeposits were analysed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. In addition, to understand the interactions of Sb3+ species with the other components of the plating solution, models were created and calculated using density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM). The results of the voltammetric behaviour of Sb3+ species indicated that the reduction potential was shifted towards more positive values with increasing water content on the electrolyte, indicating that the water catalyses the electrochemical reduction of the Sb3+ species. The values of the diffusion coefficients for the Sb3+ species were calculated by applying the Cottrell equation, which increased with the addition of water and temperature increment. The water content and temperature increase affect the surface morphologies of the Sb electrodeposited coatings, which is attributed to the improvement of Sb electrodeposition rate. Moreover, Sb electrodeposited coatings were successfully obtained without adding a complexing agent, indicating that the procedure adopted for the Sb electrodeposition is environmentally friendly. The XRD results revealed the pure phase Sb films. DFT simulations indicated that the Sb-Cl interaction is stronger, which suggests the formation of Sb-Cl complexes. Adding H 2 O molecules favours the electron affinity of the systems, and QTAIM results suggested that this additive decreased the electron density of Sb3+ ions. [ABSTRACT FROM AUTHOR]

• Temperature affected 6% by mass of SnIn coatings; • When used as soldier for electronic applications Sn-rich phase (InSn4) is most common; • The phase CuIn suggests high electrical conductivity of the coatings; • The nature of the Sn-Cl interactions was intermolecular; • Excellent theoretical–experimental correlation occurred among the systems. The objective of this work was to electrodeposit Sn-In coatings using a deep eutectic solvent consisting of choline chloride (ChCl), and ethylene glycol (EG) in the ratio 1:2 and to characterize the electrolytes employed, both experimentally and theoretically. Solutions containing 0.025 mol/L SnCl 2 and/or 0.025 mol/L InCl 3 in 1ChCl:2EG were studied by cyclic voltammetry and chronoamperometry. The diffusion coefficients of the metal ions were measured at temperatures between 297 and 343 K, with the values for Sn2+ being between 3.5 × 10−7 and 5.4 × 10−7 cm2 s−1 and between 0.90 × 10−7 and 1.46 × 10−7 cm2 s−1 for In3+. The morphology and chemical composition of Sn, In and Sn-In electrodeposits were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), the latter showing that Sn as the more noble metal was deposited preferentially. X-ray diffraction (XRD) showed the presence of an InSn 4 intermetallic phase. Furthermore, to understand better the species present in the solution, the behaviour of Sn2+ and In3+ ions was theoretically analysed through computational simulations involving molecular dynamics, density functional theory and quantum theory of atoms in molecules at four different temperatures. The results indicated that both ions (Sn2+ and In3+) interacted more strongly with the Cl− ion (In-Cl and Sn-Cl) than with ethylene glycol (In-(O1, O2) and Sn-(O1, O2) and showed no interaction with choline (In-O3 and Sn-O3). [ABSTRACT FROM AUTHOR]

Dimethyl fumarate (DMF) is the main fumaric acid ester of the Fumaderm advanced medicament for the treatment of psoriasis and multiple sclerosis. Many properties of the DMF molecule and its crystal are still unknown. Here, the structural, electronic, and optical properties of DMF in molecular form and in the form of triclinic van der Waals crystals are addressed within the framework of density functional theory (DFT) formalism. The computations were performed using local density and generalized gradient exchange-correlation functionals, LDA and GGA, respectively, including one dispersion correction scheme for the former and two for the latter. Besides, the Δ-sol correction method was applied to improve the band-gap energy estimated from the DFT computations. The UV/Vis spectra of the DMF molecule solvated in ethanol and in the crystal were measured and compared with theoretical data obtained from time-dependent DFT (molecule) and DFT (crystal) calculations. One of the dispersion-corrected GGA functionals achieved very accurate descriptions of the lattice parameters, while analysis of the Kohn–Sham band structure indicated that the DMF crystal has a direct band-gap energy of 3.12 eV, differing from the experimental band-gap (4.00 eV) by 0.88 eV. By applying the Δ-sol correction method, the band-gap energy increased to 3.95 eV, only 0.05 eV below the experimental value. Lastly, simulations were also carried out for a single DMF monolayer, for which a band-gap of 3.26 eV was predicted. Hence, intermolecular interactions tend to decrease the electronic energy gap according to the sequence Gapcrystal < Gapmonolayer < Gapmolecule. [Display omitted] • Accurate description of the DMF crystal structure was achieved using dispersion corrected DFT. • Δ-sol correction predicts the DMF gap band accurately. • A comparison of the electronic properties of solid state DMF with a 2D DMF plane and single molecule was performed. • Intermolecular interactions tend to decrease the electronic band gap of DMF systems. • DMF crystal exhibit Strong optical response for light polarized along the 110 and 010 planes. [ABSTRACT FROM AUTHOR]

• Structural and spectroscopic characterization of a chalcone. • NMR, FT-IR, and UV–Vis spectra were analyzed by DFT calculations. • Conformational analysis, and in vitro and in silico study were carried out. • The chalcone is more active on the trypomastigote form. • The chalcone has LC 50 value very smallest than the LC 50 value of the benznidazole. There is an urgent need for new inhibitors against T. cruzi , a protozoal infection that affects about 8 million people annually around the world. In this study, we describe the synthesis, characterization, and the inhibitory effects of the chalcone (E)-1-(4-aminophenyl)-3-(benzo[ b ]thiophen-2-yl)prop‑2-en-1-one (BNZTHP) against T. cruzi Y strain forms. The molecular structure of this compound was characterized by spectroscopic techniques, and its potential against T. cruzi was evaluated by in vitro assays and in silico analysis. The structural data analyses allowed drawing the molecular structure of the BNZTHP chalcone. Computational quantum chemical calculations provided the normal modes of vibrations, the global chemical reactivity parameters, the most probable regions for electrophilic and nucleophilic reactive attacks, and the singlet states for BNZTHP chalcone. Regarding the activity against T. cruzi the compound exhibited more active on trypomastigote than epimastigote forms with lower toxic on LLC-MK2 host cells. Furthermore, it presented a more powerful inhibitory effect than benznidazole. From the molecular docking studies showed that trypomastigote forms were able to interact with the cruzain, trypanothione reductase, and TcGAPDH enzymes, indicating good affinity toward the active pocket. These results bring attention to the BNZTHP chalcone as candidate for the development of new option for the treatment of Chagas disease. [Display omitted] [ABSTRACT FROM AUTHOR]

• Bis-chalcones DB ethoxy and DB chlorine were synthetized • DFT calculations were done • Characterization by NMR, Raman, IR and complete vibrational assignment is provided • Cytotoxicity promising results against cancer cells HCT-116 • Druglikeness tests passed all Lipinski R05 rules Dibenzalacetone derivatives are organic compounds formed by two α , α ′ active sites that provide a large relocation of π-electrons. They have great polarizability that make them excellent chromophore and draw attention for their biological properties, mainly for their activity against nasopharyngeal, oral, colon, prostate and cervical cancer. Two dibenzalacetone derivatives, (1E,4E)-1,5-bis(4-ethoxyphenyl)penta-1,4-dien-3-one and (1E,4E)-1,5-bis(4-chlorophenyl)penta-1,4-dien-3-one, were synthesized. Spectroscopic characterizations as well as vibrational assignments were predicted using density Functional Theory (DFT) calculations with B3LYP exchange-correlation functional. Cytotoxicity assays of the synthesized compounds were performed against HCT-116, SNB and PC3 cells, showing promising results against cancer cells HCT-116. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• Phenolic compounds and PDA were used as antioxidants and corrosion inhibitors in biodiesel samples. • A theoretical study was carried out based on the formalism of the functional density theory. • PDA showed the highest anti-corrosion potential among the studied additives. • 500 mg/kg of additive improved the stability of biodiesel samples. The objective of this work is to evaluate the effect of the addition of N,N′-di- sec -butyl-p-phenylenediamine (PDA), IONOL, and hydrogenated cardanol (HC) (500 mg/kg, each) on the oxidative stability and corrosivity of biodiesel obtained from babassu oil (BB) and from residual frying oil (BRFO). Oxidative stability was assessed by induction period (IP) using the Rancimat method (EN 14112), while the corrosivity was assessed by the mass losses of copper coupons immersed in the biodiesel samples (ASTM TM0169/G31-12a (2010)). The most severe corrosion was observed for the fresh biodiesel samples without any additives (4.85 mpy for BB, and 5.00 mpy for BRFO). Using PDA, IONOL, and HC as additives inhibited the copper corrosion in both biodiesel samples (between 0.61 and 3.09 mpy for BB, and between 2.19 and 4.69 mpy for BRFO). The use of IONOL and PDA as additives, besides showing a decrease in corrosion rates, also improved the oxidative stability (IP values) for both biodiesel samples (by 66 and >100 h, for BB; and by 3.31 and 7.23 h, for BRFO, respectively), demonstrating that these additives have bi-functionality in these biodiesel samples. Conversely, the use of HC increased the oxidative stability for BB (by 10.82 h) but also presented a pro-oxidant effect on biodiesel obtained from residual frying oil, decreasing its IP value by ca. 18%. Finally, theoretical studies were carried out based on the formalism of the functional density theory, which confirmed that PDA has indeed the highest anti-corrosion potential among the studied additives. [ABSTRACT FROM AUTHOR]