Basis Set Research Articles

Exploring novel bromo heterocyclic scaffold and theoretical explanation of their biological actions

In this elucidation, we synthesized different heterocyclic compounds through (E)-1-(2‑bromo-4-methylphenyl)-3-(4-bromophenyl)prop‑2-en-1-one(3) which is synthesized from the aldol condensation between 4-bromobenzaldehyde and 1-(2‑bromo-4-methylphenyl)ethan-1-one in the basic condition in excellent yield. Furthermore, the chalcone 3 showed also varied activity with nitrogen nucleophiles and active methylene and displayed different heterocyclic rings which were confirmed through different spectral analyses such as FT-IR, 1HNMR, 13CNMR, and mass spectrum. Moreover, the synthesized heterocyclic exhibited antimicrobial properties against various microbial strains (Gram-positive, Gram-negative, and fungal strains) through the well diffusion methodology and comparable with Ampicillin and Mycostatin drugs. Furthermore, the synthesized compounds demonstrated various radical scavenger properties and antioxidant activities. These biological analyses demonstrated various binding energies and interactions with proteins and were validated through molecular docking studies using distinct protein pockets interaction. Additionally, the Frontier Molecular Orbitals (FMO), which are physical descriptors of optimal structures that are connected with biological evaluations and demonstrate the activities of these compounds due to presence of two bromine atom which effect on electron deficiency and increase its action which examined via the DFT/B3LYP/6-311G basis set.

Computer-aided drug design supporting sunscreen research: a showcase study using previously synthesized hybrid UV filter-antioxidant compounds.

Although quantum mechanical calculations have proven effective in accurately predicting UV absorption and assessing the antioxidant potential of compounds, the utilization of computer-aided drug design (CADD) to support sustainable synthesis research of new sunscreen active ingredients remains an area with limited exploration. Furthermore, there are ongoing concerns about the safety and effectiveness of existing sunscreens. Therefore, it remains crucial to investigate photoprotection mechanisms and develop enhanced strategies for mitigating the harmful effects of UVR exposure, improving both the safety and efficacy of sunscreen products. A previous study conducted synthesis research on eight novel hybrid compounds (I-VIII) for use in sunscreen products by molecular hybridization of trans-resveratrol (RESV), avobenzone (AVO), and octinoxate (OMC). Herein, time-dependent density functional theory (TD-DFT) calculations performed in the gas phase on the isolated hybrid compounds (I-VIII) proved to reproduce the experimental UV absorption. Resveratrol-avobenzone structure-based hybrids (I-IV) present absorption maxima in the UVB range with slight differences between them, while resveratrol-OMC structure-based hybrids (V-VIII) showed main absorption in the UVA range. Among RESV-OMC hybrids, compounds V and VI exhibited higher UV absorption intensity, and compound VIII stood out for its broad-spectrum coverage in our simulations. Furthermore, both in silico and in vitro analyses revealed that compounds VII and VIII exhibited the highest antioxidant activity, with compound I emerging as the most reactive antioxidant within RESV-AVO hybrids. The study suggests a preference for the hydrogen atom transfer (HAT) mechanism over single-electron transfer followed by proton transfer (SET-PT) in the gas phase. With a strong focus on sustainability, this approach reduces costs and minimizes effluent production in synthesis research, promoting the eco-friendly development of new sunscreen active ingredients. The SPARTAN'20 program was utilized for the geometry optimization and energy calculations of all compounds. Conformer distribution analysis was performed using the Merck molecular force field 94 (MMFF94), and geometry optimization was carried out using the parametric method 6 (PM6) followed by density functional theory (DFT/B3LYP/6-31G(d)). The antioxidant behavior of the hybrid compounds (I-VIII) was determined using the highest occupied molecular orbital (εHOMO) and the lowest unoccupied molecular orbital (εLUMO) energies, as well as the bond dissociation enthalpy (BDE), ionization potential (IP), and proton dissociation enthalpy (PDE) values, all calculated at the same level of structural optimization. TD-DFT study is carried out to calculate the excitation energy using the B3LYP functional with the 6-31G(d) basis set. The calculated transitions were convoluted with a Gaussian profile using the Gabedit program.

Carbamic acid and its dimer: A computational study.

A recent work by Marks et al. on the formation of carbamic acid in NH -CO interstellar ices pointed out its stability in the gas phase and the concomitant production of its dimer. Prompted by these results and the lack of information on these species, we have performed an accurate structural, energetic and spectroscopic investigation of carbamic acid and its dimer. For the former, the structural and spectroscopic characterization employed composite schemes based on coupled cluster (CC) calculations that account for the extrapolation to the complete basis set limit and core correlation effects. A first important outcome is the definitive confirmation of the nonplanarity of carbamic acid, then followed by an accurate estimate of its rotational and vibrational spectroscopy parameters. As far as the carbamic acid dimer is concerned, the investigation started from the identification of its most stable forms. For them, structure and vibrational properties have been evaluated using density functional theory, while a composite scheme rooted in CC theory has been employed for the energetic characterization. Our results allowed us to provide a better interpretation of the feature observed in the recent experiment mentioned above.

Energetics of the OH radical H-abstraction reactions from simple aldehydes and their geminal diol forms.

Carbonyl compounds, especially aldehydes, emitted to the atmosphere, may suffer hydration in aerosols or water droplets in clouds. At the same time, they can react with hydroxyl radicals which may add or abstract hydrogen atoms from these species. The interplay between hydration and hydrogen abstraction is studied using density functional and quantum composite theoretical methods, both in the gas phase and in simulated bulk water. The H-abstraction from the aldehydic and geminal diol forms of formaldehyde, acetaldehyde, glycolaldehyde, glyoxal, methylglyoxal, and acrolein is studied to determine whether the substituent has any noticeable effect in the preference for the abstraction of one form or another. It is found that abstraction of the H-atom adjacent to the carbonyl group gives a more stable radical than same abstraction from the geminal diol in the case of formaldehyde, acetaldehyde, and glycolaldehyde. The presence of a delocalizing group in the Cα (a carbonyl group in glyoxal and methylglyoxal, and a vinyl group in acrolein), reverts this trend, and now the abstraction of the H-atom from the geminal diol gives more stable radicals. A further study was conducted abstracting hydrogen atoms from the other different positions in the species considered, both in the aldehydic and geminal diol forms. Only in the case of glycolaldehyde, the radical formed by H-abstraction from the -CH2OH group is more stable than any of the other radical species. Abstraction of the hydrogen atom in one of the hydroxyl groups in the geminal diol is equivalent to the addition of the •OH radical to the aldehyde. It leads, in some cases, to decomposition into a smaller radical and a neutral molecule. In these cases, some interesting theoretical differences are observed between the results in gas phase and (simulated) bulk solvent, as well as with respect to the method of calculation chosen. DFT (M06-2X, B2PLYP, PW6B95), CCSD(T), and composite (CBS-QB3, jun-ChS, SCVECV-f12) methods using Dunning basis sets and extrapolation to the CBS limit were used to study the energetics of closed shell aldehydes in their keto and geminal-diol forms, as well as the radical derived from them by hydrogen abstraction. Both gas phase and simulated bulk solvent calculations were performed, in the last case using the Polarizable Continuum Model.

Unveiling the molecular insights of 2-(carboxymethyl) benzoic acid: A density functional theory approach towards structural and biological attributes

Nowadays density functional theory (DFT) is one of the best methods to explore the vibrational modes and structure of the biological system. Quantum mechanical calculations are performed using gas phase and different solvents (DMSO, methanol and water). The derived global reactive parameters, structural and topological study provides the clear insight of the 2-(Carboxymethyl) benzoic acid. Depth studies of DFT proves the existence of hydrogen bonds between donor and acceptor in the compound, which is supportive for the biological applications. In this paper, different experimental and computational simulated FT-IR, FT-Raman, UV–Vis spectral studies are used to explicate vibration assignments of the 2-(Carboxymethyl) benzoic acid. Experimentally observed vibrational frequency is compared with theoretically simulated spectrum. B3LYP method with 6–311++G (d, p) basis set is used in DFT to optimize the 2-(Carboxymethyl)benzoic acid structure. The most stable lower energy conformer is identified using potential energy surface (PES) analysis using Gaussian 16 W software. ESP, HOMO-LUMO, NBO, and QTAIM calculations have evinced an adequate electronic characterization of 2-(Carboxymethyl) benzoic acid. Further, van der Waals and steric interactions among 2-(Carboxymethyl) benzoic acid have been discussed with the help of RDG study. Hirshfeld surface studies establish the existing various interaction among molecules and total packing arrangement of the crystal structure. Due to the high biological activity score, 2-(Carboxymethyl) benzoic acid is a good therapeutic candidate. Lipophilicity analysis of 2-(Carboxymethyl)benzoic acid clearly explicates the bioactivity properties and its effective drug applications. Further, molecular docking investigates that the compound can be used as anticancer medication. The detailed DFT study of the 2-(Carboxymethyl) benzoic acid justified its biological applications of the present communication. The calculated NLO parameters of 2-(Carboxymethyl)benzoic acid evidenced for good efficacy in diverse filed application has been discussed.

Experimental and Theoretical Studies on Indigo-Dye-Modified Conjugated Polymers.

The present work reports the synthesis of indigo-dye-incorporated polyaniline (Indigo-PANI), poly(1-naphthylamine) (Indigo-PNA), poly(o-phenylenediamine) (Indigo-POPD), polypyrrole (Indigo-PPy), and polythiophene (Indigo-PTh) via an ultrasound-assisted method. The synthesized oligomers were characterized using FTIR, UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), fluorescence studies, and thermogravimetric analysis (TGA). The experimental data were theoretically compared to analyze the vibrational and electronic spectra via time-dependent density-functional theory (TD-DFT) by applying the Becke, three-parameter, and Lee-Yang-Parr (B3LYP) method with a 6-311G (d,p) basis set. The experimental, theoretical vibrational, and electronic spectra were found to be in close agreement and confirmed the successful incorporation of indigo dye in PANI, PNA, POPD, PPy, and PTh. These studies confirmed that multifunctional oligomers could be synthesized through a facile technique by incorporating dye moieties to enhance their optoelectronic properties, allowing them to be utilized as near-infrared-emitting probes for photodynamic therapy.

Comparative Linkage of Novel Anti-Tumor Pd(II) Complex with Bio-Macromulecules: Fluorescence, UV-Vis, DFT, Molecular Docking and Molecular Dynamics Simulation Studies.

A novel mononuclear palladium complex, [Pd(dach)(SSA)], where dach and SSA are diaminocyclohexane and sulfosalicylic acid ligands, respectively, has been synthesized and identified utilizing analytical and spectral methods. DFT calculations, namely geometry optimization, MEP, HOMO-LUMO and NBO analysis, have been conducted at B3LYP level by aug-ccpVTZ-PP and 6-311G(d, p) basis sets. NBO and HOMO-LUMO analysis exhibited that the palladium compound is stable. MEP showed the potential sites of molecule for the interaction. By employing MTT assay, the cytotoxicity activity of the aforesaid compound was examined on K562 cell line, which revealed a proper activity compared to cisplatin. To ascertain the lipophilicity of the newly made compound, the partition coefficient measurement was accomplished, which follows the order of cisplatin < Pd(II) complex. Next, investigation of binding properties of the studied compound with DNA of calf thymus and BSA were done by spectroscopic (CD, fluorescence emission and electronic adsorption) and non-spectroscopic (viscosity measurements, DNA gel electrophoresis, molecular docking and molecular dynamics simulation) methods. The outcomes of CD and UV-Vis spectroscopy demonstrated that the title compound refolded the protein via increasing the alpha helix percentage. The data obtained from UV-Vis studies indicated the non-intercalative mutual action between Pd(II) complex with DNA. It also revealed that the Kapp magnitude of CT-DNA (7.43 × 104 M- 1) is higher than the BSA (5.17 × 103 M- 1), and L1/2 (midpoint of transition) of CT-DNA (5 µM) is lower than the BSA (5.7 µM), indicating that the complex has a greater binding affinity to CT-DNA than BSA. Fluorescence quenching mechanism of the two biomolecules by the metal complex is static and the calculated thermodynamic parameters (ΔS° < 0 and ΔH° < 0) suggested the hydrogen bonding and/ or van der Waals forces with DNA and BSA. Further, molecular docking indicated that the studied compound fits into the groove of DNA and the site I of BSA. The stability of metal compound-DNA/-BSA in the presence of H2O solvent and over the time were validated via molecular dynamics simulation.

Periodic DFT calculations to compute the attributes of a quantum material: honeycomb ruthenium trichloride.

Quantum spin liquids (QSLs) have become prominent materials of interest in the pursuit of fault-tolerant materials for quantum computing applications. This is due to the fact that these materials are theorized to host an interesting variety of quantum phenomena such as quasi-particles that may behave as anyons as a result of the high entangled nature of the spin states within the systems. Computing the electronic and magnetic properties of these materials is necessary in order to understand the underlying interactions of the materials. In this paper, the structural, electronic, and magnetic properties including lattice parameters, bandgap, Heisenberg coupling constants, and Curie temperatures for α-RuCl3, a promising candidate for the Kitaev QSL model, are computed using periodic density functional theory. Furthermore, various parameters of the calculations (i.e. functional choice, basis set, k-point density, and Hubbard correction) are varied in order to determine what effect, if any, the computational setup has on the computed properties. The results of this study indicate that PBE functional with Hubbard corrections of 1.5-2.5 eV with a k-point density of 3.0 points per Å-1 appear to be the best parameters to compute Heisenberg coupling constants for α-RuCl3. These parameters with the addition of spin orbit coupling works well for computing Curie temperatures for α-RuCl3. Distinct differences are noted in the computations of the bulk structure vs. monolayer structures, indicating that interactions between the layers play a role in the material properties and changes to the inter-layer spacing may result in interesting and unique magnetic properties that require further investigation.

Accurate structures and rotational constants of bicyclic monoterpenes at DFT cost by means of the bond-corrected Pisa composite scheme (BPCS).

The structural, conformational, and spectroscopic properties in the gas phase of 20 bicyclic monoterpenes and monoterpenoids have been analyzed by a new accurate, reduced-cost computational strategy. In detail, the revDSD-PBEP86 double-hybrid functional in conjunction with the D3BJ empirical dispersion corrections and a suitable triple-zeta basis set provides accurate geometrical parameters, whence equilibrium rotational constants, which are further improved by proper account of core-valence correlation. Average deviations within 0.1% between computed and experimental rotational constants are reached when taking into account the vibrational corrections obtained by the B3LYP functional in conjunction with a double-zeta basis set in the framework of second-order vibrational perturbation theory. In addition to their intrinsic interest, the studied terpenes further extend the panel of systems for which the proposed strategy has provided accurate results at density functional theory cost. Therefore, a very accurate yet robust and user-friendly tool is now available for systematic investigations of the role of stereo-electronic effects on the properties of large systems of current technological and/or biological interest by experimentally oriented researchers.

Mechanism, thermochemistry, and kinetics of formation of PhC(O)H and HOPhC(O)H during unimolecular decomposition of P-PhC(O2•)HPhOH.

Bisphenols are one of the main components of bio-oil, produced during the pyrolysis of lignin-containing biomass. Synthetic bisphenols are used in polycarbonate plastics, epoxy resins, and thermal papers. Their mechanism of oxidation is important for the determination of the fire safety of these materials and the possibility of using them as additives in fuels for the decrease and description of ignition delays, as well as for the determination of their health risk assessment in medicine. One representative of bisphenols is p-benzylphenol (p-PhCH2PhOH), which is formed during the fast pyrolysis of lignine-containing biomass. Its thermochemistry of oxidation has been partially studied previously. It is shown that the reaction of chain oxidation of p-PhCH2PhOH is thermochemically favorable at low temperatures. However, these studies consider only two pathways of this reaction: (1) the chain oxidation of RH by RO2• and (2) the tautomerization of R'HO2• to R'O2H with following production of R'O• and OH radicals. At the same time, the reactions of intramolecular rearrangement of RO2•, produced PhC(O)H and •PhOH or HOPhC(O)H and •Ph, are not reported but can be an important part of its oxidation mechanism. The five DFT (M06-2X (i = 1), B3LYP (i = 2), wB97XD (i = 3), M08HX (i = 4), MN15 (i = 5)) approaches with 6-311 + + G(d,p) basis set are used for the determination of standard enthalpies of atomization (ΔraH°(Xi)) of considered compounds (molecules, radicals, and transition states). These values of ΔraH°(Xi) are corrected using the empirical linear calibration dependencies, reported previously. The different calibration dependencies are used for the hydrocarbons (including the aromatics and simple oxygenated derivatives) and for the peroxides. The corrected values of ΔraH°(Xi, CORR) are used according to Hess's law for the determination of ΔfH°(Xi, CORR). The most consistent values of ΔfH°(X, MEAN) are derived from the coordination of the values of ΔfH°(Xi,CORR) using the intersection of their values of standard deviations (3SDi). These values of ΔfH°(X, MEAN), as well as the B3LYP values of S°(X), which are accounting the frequencies correction and internal rotations, as well as their temperature dependencies, are used for the determination of thermochemistry of considered reactions and of the calculation, within transition state theory (TST), of the values of high pressure limits of the rate constant. The values of H°(Xi), S°(Xi), and G°(Xi) are calculated using the Gaussian 16w program. The considered mechanism is prepared using ISIS/Draw package. The temperature dependencies of thermochemical properties and the values of rate constants are determined using the ChemRate program (v.1.5). The optimized structures are visualized using the Chemcraft package.

Investigation on the Influence of Solvents Environment on the Optoelectronic Properties of the Fluorescent Probe 1,3,4-Oxadiazole Analogues: A Combined Theoretical and Experimental Study.

This study investigates the photophysical properties of a nitrobenzene-substituted 1,3,4-oxadiazole derivative (OX-NO) using both theoretical and experimental methods. The impact of the solvent on OX-NO absorption and fluorescence spectra, as well as its fluorescence quantum yield, was initially studied. A noticeable bathochromic shift in the Stokes shift indicated a π→ π* transition within the molecules. Solute-solvent interactions were analysed using Catalan parameters, distinguishing between specific and nonspecific interactions. Excited state dipole moments were derived from Lippert's, Bakshiev's, and Chamma Viallet's equations, showing increased polarity in the excited state compared to the ground state. Ground state dipole moments were determined via solvatochromic shift methods and ab initio techniques. Additionally, detailed analyses of bond length, angles, dihedral angles, Mulliken charge distribution, and HOMO-LUMO energy gap were conducted using the DFT-B3LYP-6-311G basis set in Gaussian-09W. The energy band gap values obtained from theoretical calculations and experimental methods (cyclic voltammetry and UV-Visible spectroscopy) exhibited excellent agreement. Reactive sites such as electrophilic and nucleophilic regions were identified through total electron density, electrostatic maps, molecular electrostatic potential, and 3D plots using DFT computational analysis. Global descriptors were employed to characterize the compounds' chemical reactivity comprehensively. The observed photophysical attributes underscore the potential of these fluorophores in various applications like organic light-emitting diodes, solar cells, and chemosensors. This study contributes crucial insights into the optoelectronic properties of nitrobenzene-substituted 1,3,4-oxadiazole derivatives, paving the way for their future integration in advanced technological domains.

Trends in hip fracture rates in spain from 2001 to 2018.

To describe the evolution of cases and rates of hip fracture (HF) in patients 65 years or older in Spain from 2001 to 2018 and examine trends in adjusted rates. Retrospective, observational study including patients ≥65 years with acute HF. Data from 2001 to 2018 were obtained from the Spanish National Record of the Minimum Basic Data Set of the Ministry of Health. We analysed cases of HF, crude incidence and age-adjusted rates by sex, length of hospital stay (LOS) and in-hospital mortality, and used joinpoint regression analysis to explore temporal trends. We identified 756,308 HF cases. Mean age increased 2.5 years, LOS decreased 4.5 days and in-hospital mortality was 5.5-6.5%. Cases of HF increased by 49%. Crude rate per 100,000 was 533.3 (95% confidence interval [CI], 532.1-534.5), increasing 14.0% (95%CI, 13.7-14.2). Age-adjusted HF incidence rate increased by 6.9% from 2001 (535.7; 95%CI, 529.9-541.5) to 2005 (572.4; 95%CI, 566.7-578.2), then decreased by 13.3% until 2017 (496.1, 95%CI, 491.7-500.6). Joinpoint regression analysis indicated a progressive increase in age-adjusted incidence rates of 1.9% per year from 2001 to 2005 and a progressive decrease of -1.1% per year from 2005 to 2018. A similar pattern was identified in both sexes. Crude incidence rates of HF in Spain in persons ≥65 years from 2001 to 2018 have gradually increased. Age-adjusted rates show a significant increase from 2001 to 2005 and a progressive decrease from 2005 to 2018.

Efficient and practical quantum compiler towards multi-qubit systems with deep reinforcement learning ∗ ∗The authors list is in alphabetical order.

Efficient quantum compiling is essential for complex quantum algorithms realization. The Solovay–Kitaev (S–K) theorem offers a theoretical lower bound on the required operations for approaching any unitary operator. However, it is still an open question that this lower bound can be actually reached in practice. Here, we present an efficient quantum compiler which, for the first time, approaches the S–K lower bound in practical implementations, both for single-qubit and two-qubit scenarios, marking a significant milestone. Our compiler leverages deep reinforcement learning (RL) techniques to address current limitations in terms of optimality and inference time. Furthermore, we show that our compiler is versatile by demonstrating comparable performance between inverse-free basis sets, which is always the case in real quantum devices, and inverse-closed sets. Our findings also emphasize the often-neglected constant term in scaling laws, bridging the gap between theory and practice in quantum compiling. These results highlight the potential of RL-based quantum compilers, offering efficiency and practicality while contributing novel insights to quantum compiling theory.

Prediction of Redox Potentials for U, Np, Pu, and Am in Aqueous Solution.

The redox properties of the actinides in aqueous solution are important for fuel production/reprocessing and understanding the environmental impact of nuclear waste. The redox potentials for U, Np, Pu, and Am in oxidation states from 0 up to VII (as appropriate) in aqueous solutions have been predicted at the density functional theory level with the B3LYP functional, Stuttgart small core pseudopotential basis sets for the actinides, and explicit (30H2O molecules)/implicit treatment of the aqueous solvent using the self-consistent reaction field COSMO and SMD approaches for the implicit solvation. The predictions of the structural parameters of clusters incorporating first and second solvation shells are consistent with the available experimental data. Our results are typically within 0.2 V of the available experimental data using two explicit solvation shells with an implicit solvent model. The use of the PW91 functional substantially improved the prediction of the Pu(VI/V) redox couple. The redox couples for An(VI/IV) and An(V/IV) which involve the addition of protons and removal of the actinyl oxygens led to slightly larger differences from an experiment. The An(IV/0) and An(III/0) couples were reliably predicted with our approach. Predictions of the unknown An(II/I) redox potentials were negative, consistent with expectations, and predictions for unknown An(VII/VI), An(III/II), and An(II/0) redox couples improve prior estimates.

Impact of doping with organic dopants and mixed doping with alkali metals and organic dopants on the absorption, electronic, optoelectronic, thermodynamic and nonlinear optical properties of dibenzo[b,def]chrysene in gaseous media: DFT and TD-DFT studies.

In this study, we evaluate the geometrical, absorption, optoelectronic, electronic, nonlinear optical (NLO) and thermodynamic properties of dibenzo[b,def]chrysene molecule derivatives by means of DFT and TD-DFT simulations. In view of the aim of producing new high-performance materials for non-linear optics (NLO) by doping test, two types of doping were used. We obtained six derivatives by doping with organic dopants (Nitro, amide and ticyanoethenyl) and mixed alkali metal (potassium) and organic dopants. Doping with organic dopants produced molecules A, B and C, respectively when substituting one hydrogen with nitro (NO2), amide (CONH2) and tricyanoethenyl (C5N3) groups, while mixed doping involved considering A, B and C and then substituting two hydrogens with two potassiums to obtain compounds D, E and F respectively. The negative values of the various interaction energies calculated for all the doped molecules show that they are all stable, but also that molecules C and F are the most stable in the case of both dopings. The gap energies calculated at the B3LYP level of theory are all below 3eV, which means that all the molecules obtained are semiconductors. Better still, compounds C and F, with gap energies of 1.852eV and 1.204eV, respectively, corresponding to decreases of 35.67% and 58.18% in gap energy compared with the pristine molecule, are more reactive than the other doped molecules. Mixed doping is therefore a highly effective way of narrowing the energy gap and boosting the semiconducting character and reactivity of organic materials. Optoelectronic properties have also been improved, with refractive index values higher than those of the reference material, glass. This shows that our compounds could be used under very high electric field conditions of the order of 4.164 109V.m-1 for C and 7.410 109V.m-1 for F the highest values at the B3LYP level of theory. The maximum first-order hyperpolarizability values for both types of doping are obtained at the CAM-B3LYP level of theory by C: 10-30esu and by F: 10-30esu, and second-order values are also given by these same compounds. These values are higher than the reference value, which is urea, making our compounds potential candidates for high-performance NLO applications. In dynamic mode and at a frequency of 1064nm, at the CAM-B3LYP level of theory, the highest dynamic hyperpolarizability coefficients were obtained by C and F. Hyper-Rayleigh scattering , coefficients of the electro-optical Pockel effect (EOPE), EFISHG, third-order NLO-response degree four-wave mixing , quadratic nonlinear refractive index n2 were also calculated. The maximum values of n2 are obtained by C (6.13 10-20 m2/W) and F (6.60 10-20 m2/W), these values are 2.24 times higher than that of fused silica which is the reference for degenerate four-wave mixing so our molecules could also have applications in optoelectronics as wavelength converters, optical pulse modulators and optical switches. Using the DFT method, we were able to determine the optimized and stable electronic structures of doped dibenzo[b,def]chrysene derivatives in the gas phase. We limited ourselves to using the proven B3LYP and CAMB3LYP levels of theory for calculating electronic properties, and non-linear optics with the 6-311G + + (d,p) basis set, which is a large basis set frequently used for these types of compound. Gaussian 09 software was used to run our calculations, and Gauss View 6.0.16 was used to visualize the output files. TD-DFT was also used to determine absorption properties at the B3LYP level of theory, using the same basis set.

Virtual screening, molecular docking, MD simulation studies, DFT calculations, ADMET, and drug likeness of Diaza-adamantane as potential MAPKERK inhibitors.

Introduction: Multiple sclerosis (MS) is an autoimmune and inflammatory disease that destroys the protective coating of central nervous system (CNS) nerve fibers and affects over 2.8 million people worldwide. Despite several studies on new therapeutic targets and lead compounds, MS disease has limited treatment options. This condition may be caused by a complicated interaction of environmental and genetic variables. Studies showed that MS-associated microglial cells' increased MAPKERK activity may cause CNS inflammation and oligodendrocyte damage. Thus, screening for lead compounds that inhibit MAPKERK may protect brain cells and slow disease progression. Methods: The study aims to discover compounds that may inhibit MAPKERK as a novel approach for protecting the nervous system in managing MS. The study includes in silico methods, such as virtual screening, molecular docking, Density-functional theory (DFT) investigations (using the B3LYP/6-31++G(d,p) basis set in a gas phase environment), drug likeness scores, and molecular dynamic (MD) simulations. Results and Discussion:During the docking process with the MAPKERK protein, it was shown that the ligand L12 receptor had the best binding affinity, with a docking score of -6.18kcal/mol. To investigate the stability of the binding, a 100ns MD simulation was performed on the complex formed by the MAPKERK protein and L12. The receptor-ligand combination exhibited significant stability throughout the duration of the MD simulation. Additionally, the pharmacokinetic and drug-likeness properties of these ligands suggest that they have the potential to be considered viable candidates for future development in MS management.

Ab initio investigation on the mechanism of SO2 activation by P/B intermolecular frustrated Lewis pairs.

In silico study investigates the activation of sulfur dioxide by newly designed frustrated Lewis pairs, i.e., [P(tBu)3…B(C2NBSHF2)3], where the Lewis acid part is a super Lewis acid. The activation process involves the making of P-S and B-O bonds, leading to the formation of an FLP-SO2 adduct. The calculated results demonstrate that the activation of SO2 by the FLP is almost barrierless and exothermic. Exploration of the impact of the solvent environment on the feasibility and energetics of the reaction has been investigated. The exothermicity is increasing in nonpolar solvents. This study focuses on understanding the electronic activity of SO2 activation by FLP with the help of the Minnesota 06 functional, M06-2X (global hybrid functional with 54% HF exchange) along with Pople's basis set, 6-311G (d, p). Principal interacting orbital and extended transition state-natural orbitals for chemical valence studies, giving impactful insight into the favorable orbital interaction and electron transfer in this reaction. Furthermore, useful CDFT descriptors such as reaction force constant and reaction electronic flux profiles along the intrinsic reaction coordinate give insights into the synchronicity and total electronic activity of the reaction.

Exploration of the synergistic effect of chrysene-based core and benzothiophene acceptors on photovoltaic properties of organic solar cells

To improve the efficacy of organic solar cells (OSCs), novel small acceptor molecules (CTD1–CTD7) were designed by modification at the terminal acceptors of reference compound CTR. The optoelectronic properties of the investigated compounds (CTD1–CTD7) were accomplished by employing density functional theory (DFT) in combination with time-dependent density functional theory (TD-DFT). The M06 functional along with a 6-311G(d,p) basis set was utilized for calculating various parameters such as: frontier molecular orbitals (FMO), absorption maxima (λmax), binding energy (Eb), transition density matrix (TDM), density of states (DOS), and open circuit voltage (Voc) of entitled chromophores. A red shift in the absorption spectra of all designed chromophores (CTD1–CTD7) was observed as compared to CTR, accompanied by low excitation energy. Particularly, CTD4 was characterized by the highest λmax value of 685.791 nm and the lowest transition energy value of 1.801 eV which might be ascribed to the robust electron-withdrawing end-capped acceptor group. The observed reduced binding energy (Eb) was linked to an elevated rate of exciton dissociation and substantial charge transfer from central core in HOMO towards terminal acceptors in LUMO. These results were further supported by the outcomes from TDM and DOS analyses. Among all entitled chromophores, CTD4 exhibited bathochromic shift (685.791 nm), minimum HOMO/LUMO band gap of 2.347 eV with greater CT. Thus, it can be concluded that by employing molecular engineering with efficient acceptor moieties, the efficiency of photovoltaic materials could be improved.

QUANTUM CHEMICAL STUDY OF THE ELECTRONIC STRUCTURE OF YTTERBIUM HALIDES

The study of ytterbium halide crystals using the compound-tunable embedding potential (CTEP) method is carried out in the framework of the density functional theory. For subsequent calculations using the coupled-cluster methods, the optimization of atomic bases is carried out, and for this purpose stochiometric molecular systems were studied. The chemical shift of the lines of the X-ray emission spectrum, Kα1 and Kα2, in YbHal3 relative to YbHal2 was chosen as a criterion for verifying the computational accuracy of the properties localized on the nucleus of a heavy atom, Yb, since this method is a unique tool for analyzing partial electron densities near a heavy nucleus speci cally for compounds of d- and f-elements. In the study, ve main versions for the halogen basis set sizes were considered. The stability of the results was obtained using the CCSD and CCSD(T) coupled cluster methods for molecular systems YbF2, YbF3, YbCl2, YbCl3.

UNDULATING POTENTIALS OF RYDBERG Σ+-STATES OF ME-RG MOLECULES: NON-EMPIRICAL TREATMENT OF NA-HE EXCIPLEX

The multi-reference con guration interaction method based on single and double excitations (MR-CISD), l-independent core polarization potential (CPP) and diffuse function-saturated cc-pVQZ and aug-cc-pV5Z basis sets for Na and He atoms, respectively, have been used to perform non-relativistic calculations of potential energy curves and permanent dipole moment functions for the ground and excited electronic states of the exciplex Na-He molecule up to the Na(62S) state. The ab initio results obtained in a wide range of internuclear distances R [1.7, 20.0] (Å) have quantitatively claimed the undulating behavior of interatomic potentials, predicted within the framework of the inelastic scattering theory. It has been established that at large R the interatomic potentials and dipole moments of highly excited (3,6,10)2Σ+ states, converging to Na (n = 4, 5, 62S)+He(22S) atomic limits, are modulated by the nodal structure of the radial Rydberg wave function (n &gt; 3) s-electron of Na atom during its scattering on the remote He atom.