Molecular Orbital Surfaces Research Articles

A theoretical investigation into the impact of solvents (alkanolic and non-alkanolic), structural and spectroscopic properties, donor-acceptor insights, Hirshfeld surface, and molecular docking of the anti-tumor compound (2E)-3-[4-(dimethylamino)phenyl]-1-(3-nitrophenyl)prop‑2-en-1-one

In this study, computational methods were employed to analyze the molecular structure of (2E)-3-[4-(Dimethylamino)phenyl]-1-(3-nitrophenyl)prop-2-en-1-one (DMAPNP), investigating its structural and spectroscopic properties along with its biological activity. In particular, the Frontier Molecular Orbital (FMO) and Molecular Electrostatic Potential (MEP) surfaces in alkanolic solvents (ethanediol, ethanol, and methanol) and non-alkanolic solvents (DMSO, toluene, and water) were generated to analyze the solvent-solute interactions. The H→L transition shows low oscillator strengths (0.0002 in toluene to 0.0013 in ethanediol, DMSO, and water), indicating limited significance in the absorption spectrum. In contrast, the H→L+1 transition has much higher oscillator strengths, around 0.9412 for ethanediol and 0.9385 for DMSO and toluene, suggesting a greater likelihood of absorption at these wavelengths. The simulated vibrational wavenumbers revealed the presence of CH, NO2, CN, CC, CH3, and C=O groups in DMAPNP. The calculated chemical shifts confirmed the molecular structure of DMAPNP and aligned with standard values. In Hirshfeld surface analysis, the crystal packing of DMAPNP was primarily stabilized by H…H interactions, contributing 41.3%, followed by O…H / H…O interactions at 30.9%. In Natural Bond Orbital (NBO) analysis, the interaction between C20-H38 and C15-H33 shows a stabilization energy of 1102.89 kJ/mol, highlighting σ-σ* transitions. In contrast, the C12-C16 and C15-H33 interactions exhibit a stabilization energy of 2542.16 kJ/mol, indicating substantial π-σ* contributions. In the Mulliken charge distribution, the carbon atoms C18 (-1.33704e) and C13 (1.776064e), located in the para and meta positions concerning the nitro group (NO2), exhibit the highest positive and negative potentials, respectively. Molecular docking assessed DMAPNP as a potential anti-tumor agent by inhibiting the key regulatory enzyme fructose-2,6-bisphosphatase, with a binding energy of -8.13 kcal/mol.

Hydrogen bond thermotropic ferroelectric liquid crystal of DL-tartaric acid and 4-heptyloxybenzoic acid (1:1): Experimental and density functional theory (DFT) approach

The current research work incorporates structural, experimental and computational studies of a hydrogen bond thermotropic ferroelectric liquid crystal (HBTFLC) complex synthesised from DL-tartaric acid (DLTA) and 4-heptyloxybenzoic acid (7OBA) with 1:1 ratio. Spectroscopic studies (XRD, NMR, FTIR, UV–Vis) and Density Functional Theory (DFT) are utilized to confirm intermolecular hydrogen bonds in the synthesised complex. Polarizing Optical Microscope (POM) study confirms the phase sequence (N*, Sm C*, Sm F* and Sm G*) while Differential Scanning Calorimetry (DSC) explore the thermal properties of the mesophases. The Frontier Molecular Orbital (FMO) and Molecular Electrostatic Potential (MEP) surface analysis also explore the donor-acceptor interactions, stability and chemical reactivity of the complex. The nature of H-bond is estimated by Natural Bond Orbital (NBO) studies with the support of Atom-in-Molecules (AIM) and Reduced Density Gradient (RDG) analysis. Nonlinear Optical (NLO) properties of the complex are studied by calculating its polarizability and hyperpolarizability.

Synthesis, structural characterization, Hirshfeld surface, DFT calculation and antifungal activity of novel quinoline carbonothioate compounds

Three quinoline carbonothioate compounds were synthesized using o-fluoroaniline and ethyl 2-methylacetoacetate as starting materials via multi-steps. The structures of three compounds were confirmed using 1H NMR and HRMS. The structure of O-ethyl S-(8-fluoro-2,3-dimethylquinolin-4-yl) carbonothioate (3a) was further determined through X-ray single-crystal diffraction. Single-crystal X-ray diffraction analysis indicated that compound 3a crystallizes in the monoclinic space group C2/c, with unit cell parameters: a = 14.3284(6) Å, b = 19.2857(8) Å, c = 10.3990(5) Å, β = 108.1220(10)°, V = 2731.0(2) Å3. In addition, the physicochemical properties of compound 3a were calculated and discussed using molecular electrostatic potential, frontier molecular orbital and Hirshfeld surface analysis. The antifungal activity of the three compounds was evaluated at 50 μg/mL, with compound 3b exhibiting good activity (75.8%) against R. solani.

New Charge-Transfer Complexes of Organochalcogenide Compound Based on Aryl Acetamide Group with Quinones: Synthesis, Characterization, Antioxidant, and Computational Study

This study aims to prepare charge transfer complexes derived from organochalcogenide of arylamide derivatives with different quinones. A new charge-transfer complexes have been developed through a direct reaction between (PhNHCOCH2)2Se, (o-CH3PhNHCOCH2)2Se, and (PhCH2NHCOCH2)2E, where E = S, Se, and Te are electron donors and different quinones are electron acceptors. The quinones used in the reaction were 2,3-dichloro-5,6-dicyanobenzoquinones (DDQ), 7,7’,8,8’-tetracyanoquinodimethane, and tetracyanoethane. The electron donors and electron acceptor mol were 1:1, and the reaction was conducted in acetonitrile. Infrared, 1H and 13C-NMR spectroscopic data characterized all complexes. The complexes’ antioxidant activity was evaluated through α,α-diphenyl-β-picrylhydrazyl at 10–0.312 mg/mL. The results showed that all complexes exhibited promising antioxidant activities. Among them, (PhCH2NHCOCH2)2S·DDQ compound had the least IC50 value of 6.725 mg/mL, indicating a potent scavenging property compared to other compounds. The molecular structures of charge-transfer complexes were investigated using hybrid density functional theory (B3LYP) and basis set 3-21G. We obtained geometrical structures' highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) surfaces and energy gaps through geometric optimization. We also investigated the molecular shapes and contours of the prepared compounds through geometrical optimization and compared the HOMO energy of the CT compounds to investigate donor and acceptor properties.

Synthesis, crystal and molecular structures, DFT calculations, spectroscopic (IR, NMR, UV–Vis), vibrational properties and Hirshfeld surface and antitumor activity of two pyrazole boronic acid pinacol ester compounds

In this study, title compounds 1-(cyclopropylsulfonyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (A) and N,N-dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole-1-sulfonamide (B) were synthesized by a one-step reaction, and their structures were determined using FT-IR, 1H NMR, 13C NMR spectra, MS and X-ray single crystal diffraction, and the crystallography and conformational analysis were performed. The optimal structure and front-line orbital energies of compounds A and B were determined using density functional theory (DFT) in the B3LYP/6-311+G(2d, p) mode. In addition, we compared and analyzed the spectral data (13C NMR, 1H NMR, and UV–visible) by DFT and TD-DFT calculations, and studied the molecular electrostatic potential, frontier molecular orbital, vibration analysis, and Hirshfeld surface analysis of the title compounds. Finally, the proliferative effects of compounds A and B were evaluated.

Experimental and computational studies of two binuclear Co(II) and Ni(II) bis(salamo)‐like complexes

Acetate‐bridged binuclear Co(II) and Ni(II) complexes, [Co2(L)(μ‐OAc)(EtOH)] (1) and [Ni2(L)(μ‐OAc)(EtOH)] (2) were synthesized via the reaction of a new bis(salamo)‐like ligand with two different metal(II) acetates. X‐ray single crystal diffraction analyses showed that two metal(II) ions (Co or Ni) occupy two sets of N2O2 cavities, respectively. The acetate group bridges the two metals, and the ethanol oxygen atom participates in the coordination. Furthermore, UV–vis titration experiments clearly indicated that the complexation between H3L and M(II) ions leads to the 1:2 complexes [(L)M2]+ through a highly synergistic process. Bond valence sum (BVS) calculations exhibited that the Co(II) and Ni(II) ions are divalent. Secondly, the ligand H3L highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO‐LUMO) gap analysis and surface electrostatic potential were theoretically analyzed by theoretical calculation (density functional theory), and the reactivity of M(II) ions and the ligand in the complex formation process was demonstrated. Finally, the microscopic properties of the complexes were deeply understood through the calculation of the weak intramolecular interactions and the unstressed regions outside the complexes.

Insights into synthesis, structural, energetic, vibrational, anticancer activity and molecular characteristics of 2-((2-aminopyridin-3-yl)methylene)-N-phenylhydrazinecarbothioamide as evaluated using spectroscopic and DFT investigations

Synthesis of 2-((2-aminopyridin-3-yl)methylene)-N-phenylhydrazinecarbothioamide (APHB) was attempted. Elemental analysis and NMR spectra were used to ascertain its formation. Torsional potential energy scans, for all the rotating bonds were made to get approximate initial values of dihedral angles. FT-IR, FT Raman, and UV–Vis spectra were measured for APHB. Their anticancer activity was determined experimentally, for human carcinoma cell lines pertaining to liver, Colorectal, and lung. Barrier heights, around six rotating bonds in APHB were computed. Optimized structure parameters, general valence force field, harmonic vibrational fundamentals, potential energy distribution, infrared and Raman intensities, frontier molecular orbital (FMO) parameters, NLO behaviour, NBO characteristics and molecular electrostatic surface potential (MESP) were determined using DFT/B3LYP/6-311++G(d,p) level of theory. TD-DFT was used to compute absorption maxima (λmax) of electronic transitions for the molecule in DMSO‑d6 solvent. Frontier molecular orbitals were used to understand origin of UV–Vis spectrum and chemical reactivity of the molecule. Good agreement was found between measured and computed structure parameters, IR, Raman and UV–Vis spectra. The rms error between experimental and theoretical vibrational frequencies was 9.5 cm−1, for APHB. All vibrational fundamentals were assigned unambiguously. The computations demonstrated that the molecule was good for NLO applications, which was substantiated by NBO analysis. Existence of bifurcated intramolecular hydrogen bond was predicted for APHB.

Study on mercury adsorption mechanism of iron-modified biomass char in coal-fired flue gas based on density functional theory

As a new type of porous adsorbent, iron-modified biomass char (Fe10%-BC) may efficiently remove Hg0 from flue gas. However, the lack of in-depth research on the mercury adsorption mechanism of biomass char limits the development of this technology. The reaction path of mercury adsorption was quantitatively revealed by DFT (Density Functional Theory). The effects of oxygen-containing groups and adsorption atmosphere on Hg0 adsorption were analyzed. The results show that Hg0 adsorption by Fe10%-BC includes two stages, that is adsorption and oxidation. The modified biochar utilized the strong oxygen release/storage capacity of iron oxides, reacting with Hg0 by Lewis acid-base reaction. Oxygen-containing groups regulated molecular orbital energy level and surface charge distribution of iron-modified biomass char, affecting the adsorption capacity of Fe10%-BC. Aldehyde, ketone and carboxyl group promoted Hg0 adsorption performance of Fe10%-BC, and the effect from strong to weak was aldehyde group > ketone group > carboxyl group. Hydroxyl group inhibited mercury adsorption by Fe%10-BC. The adsorption atmosphere CO2，O2 and HCl promoted the mercury adsorption performance of the iron-based modified biomass char by forming new adsorption sites with the modified biomass char. SO2 consumed the high valence metal and lattice oxygen, forming competitive adsorption with Hg0. Hg0 adsorption efficiency of the modified biomass char decreased to 58%.

New flavone-based arylamides as potential V600E-BRAF inhibitors: Molecular docking, DFT, and pharmacokinetic properties

ObjectivesThe V600E-BRAF protein kinase is an attractive and essential therapeutic target in melanoma and other tumors. However, because of its resistance to the known inhibitors and side effects of some identified inhibitors, new potent inhibitors need to be identified. MethodsIn the present work, in silico strategies such as the molecular docking simulation, DFT (Density-Functional-Theory) computations, and pharmacokinetic evaluation were used to determine potential V600E-BRAF inhibitors from a set of 31 synthesized novel flavone-based arylamides. ResultsThe docking result demonstrated that four compounds (10, 11, 28, and 31) had acceptable docking scores (MolDock score of −167.523 kcal mol−1, −158.168 kcal mol−1, −160.581 kcal mol−1,−162.302 kcal mol−1, and a Rerank score of −124.365, −129.365, −135.878 and −117.081, respectively) appeared as most active and potent V600E-BRAF inhibitors that topped vemurafenib (−158.139 and −118.607 kcal mol−1). The appearance of H-bonds and hydrophobic interactions with essential residues for V600E-BRAF proved the high stability of these complexes. The energy for the frontier molecular orbitals such as HOMO, LUMO, energy gap, and other reactivity parameters was computed using DFT. The frontier molecular-orbital surfaces and electrostatic potentials (EPs) were investigated to demonstrate the charge-density distributions that might be linked to anticancer activity. Similarly, the chosen compounds revealed superior pharmacological properties according to the drug-likeness rules (bioavailability) and pharmacokinetic properties. ConclusionThe chosen compounds were recognized as potent V600E-BRAF inhibitors with superior pharmacokinetic properties and could be promising cancer drug candidates.

Virtual screening, pharmacokinetic, and DFT studies of anticancer compounds as potential V600E-BRAF kinaseinhibitors

ObjectivesV600E-BRAF kinase is an essential therapeutic target in melanoma and other types of tumors. Because of its resistance to known inhibitors and the adverse effects of some identified inhibitors, investigation of new potent inhibitors is necessary. MethodsIn the present work, in silico strategies such as molecular docking simulation, pharmacokinetic evaluation, and density functional theory (DFT) computations were used to identify potential V600E-BRAF inhibitors from a set of 72 anticancer compounds in the PubChem database. ResultsFive top-ranked molecules (12, 15, 30, 31, and 35) with excellent docking scores (MolDock score ≥90 kcal mol−1, Rerank score ≥60 kcal mol−1) were selected. Several potential binding interactions were discovered between the molecules and V600E-BRAF. The formation of H-bonds and hydrophobic interactions with essential residues of V600E-BRAF suggested the high stability of these complexes. The selected compounds had excellent pharmacological properties according to the drug likeness rules (bioavailability) and pharmacokinetic properties. Similarly, the energy for the frontier molecular orbitals, such as the HOMO, LUMO, energy gap, and other reactivity parameters, was computed with DFT. The frontier molecular orbital surfaces and electrostatic potentials were investigated to demonstrate the charge-density distributions potentially associated with anticancer activity. ConclusionThe identified compounds were found to be potent hit compounds for V600E-BRAF inhibition with superior pharmacokinetic properties; therefore, they may be promising cancer drug candidates.

Novel trypanocidal thiophen-chalcone cruzain inhibitors: structure- and ligand-based studies.

Background: Chagas disease is a neglected tropical disease that affects millions of people worldwide and for which no effective treatment is available. Materials & methods: 17chalcones were synthesized, for which the inhibition of cruzain and trypanocidal activity were investigated. Results: Chalcone C8 showed the highest cruzain inhibitory (IC50=0.536μm) and trypanocidal activity (IC50=0.990μm). Molecular docking studies showed interactions involving Asp161 and the thiophen group interacting with the S2 subsite. Furthermore, quantitative structure-activity relationship (q2=0.786; r2=0.953) and density functional theory studies were carried out, and a correlation between the lowest unoccupied molecular orbital surface and trypanocidal activity was observed. Conclusion: These results demonstrate that these chalcones are worthwhile hits to be further optimized in Chagas disease drug discovery programs.

Vibrational Spectroscopic Investigations, Electronic Properties, Molecular Structure and Quantum Mechanical Study of an Antifolate Drug: Pyrimethamine

The computational modelling supported by experimental results can explain the molecular structure, vibrational assignments, reactive sites and several structural properties. In this context, the spectroscopic (FT-IR, FT-Raman and NMR) analysis, electronic properties (HOMO and LUMO energies) and molecular structure of pyrimethamine (Pyr) were investigated by density functional theory (DFT) method associated with three levels of theory viz., B3LYP, MN15 and wB97XD with 6-311++G(d,p) and def2TZVPP as basis sets, respectively in the Gaussian 16 programs. The 1H and 13C NMR chemical shifts were calculated with a gauge-independent atomic orbital (GIAO) approach by also applying the same levels of theory and basis sets. All experimental results were compared with theoretical data. Although the results revealed high degrees of correlation between the theoretical and experimental values for spectroscopic properties using the three methods. Furthermore, the atomic and natural charges, energy band gap and chemical reactivity were determined, while the frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) surfaces were plotted to explain the reactive nature of the title molecule.

A critical evaluation of [ML(ONO)]n+ (M = Fe, Ru, Os) as nitric oxide precursor influenced by spin multiplicity and geometrical parameters (M-O-NO and MO-N-O) for the NO release: A theoretical study

In cell biology, the physiological functions control blood pressure by the production of nitric oxide, and the exploitation of metal complexes such as [ML-ONO] (M = Fe2+, Ru2+, Os2+) has been motivated to study the photolytic liability of NO. The structural and electronic properties of the complexes of 1,4,8,11-tetrakis-(1-methyl-pyridyl)-1,4,8,11-tetraazacyclotetradecane were analyzed theoretically. The results show that β-cleavage of nitrito group in the complex [ML-ONO]n+ (M = Fe, Ru, Os; n = 1 or 2) favors the NO release, and observed the role of spin multiplicity. The M(II)-O-NO angle is associated with the degree of activation of the M(II)O—NO bond, relying on the excitations (S = 1 or S = 2), and it is corelated to the reduction of the bond angle ONO (~133° at S = 0) to ~ 105° at S = 1 or 2, favoring the nitrito β-cleavage for the complexes. This is consistent with orbital energy (dx2-y2) stabilizing the axial M(III)-O bond greater than that in M(II)-O [Fe < Ru ~ Os] as the excitation of singlet to triplet or to quintet prompts the NO delivery according to Gibbs free energy, agreeing with the transition state energy. However, at high spin state like 3/2 or 5/2, irrespective of bond angle M(III)-O-NO or ONO, the bond O-NO was broken spontaneously, resulting relatively a greater bond distance. Natural Transition Orbitals (NTOs), Molecular orbital (MO) Electron density contour on molecular orbital surface were also studied to understand the M-ONO bonding nature, and observed its performance in the TD-DFT electronic spectra.

Synthesis, crystal structure, DFT studies, Hirshfeld surface analysis and drug delivery performance of bis(2-chloro-4,6-diaminopyrimidine)copper(II)-dichloride

The new single crystal, bis(2-chloro-4,6-diaminopyrimidine)-copper(II)-dichloride [CDPCD] compound was synthesized. The crystal structure of the compound was solved by the single crystal X-ray diffraction method. CDPCD has a=6.3334(9) Å, b=6.9914 (10)Å, c=8.9901(12)Å, α=78.127(11)°, β=86.853(11)°, γ=67.307(10)° and Z=1 parameters and is crystallized in the space group P-1 in the triclinic crystal system. Complete vibration assignments of CDPCD in gas phase and experimental frequencies are reported together with the scaled force constants. The optimized geometric parameters and frequency values were theoretically calculated using DFT/B3LYP method with LANL2DZ basis set. The XRD single crystal measurement parameters are good agreed with the optimized parameters. Molecular orbital surfaces and molecular electrostatic potential properties were measured at B3LYP/LANL2DZ level. Hirshfeld surface and fingerprint drawings were obtained to explain the intermolecular interactions of the crystal structure. The most important contributions for the crystal packing are from Cl…H/H…Cl (38.7%), H…H (17.9%) and N…H/H…N (14.8%) interactions. In addition, the molecule was tested by MTT test to determine the apoptosis and necrosis by cytotoxicity and double staining method. For the MTT test [MTT: (3,4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide], the tetrazolium salt was used. In different percentages of the compound, apoptotic necrotic index ratios of L929 fibroblasts and MCF-7 cells decreased. Bilateral staining method was used to evaluate the cells that had undergone apoptosis and necrosis of FITC (480-520nm wavelength). Apoptotic and necrotic index results of L929 fibroblasts and MCF-7 cells decreased as the amount of concentration decreased.

Comparing molecular and electronic properties of perylene tetracarboxylic diimides decorated at 1,6- and 1,7-bay-positions using DFT/TDDFT method

Geometrical structures and singlet vertical excitations of perylene tetracarboxylic diimides decorated at 1,6- and 1,7-bay positions investigated using density functional theory and its time dependent formalism. Such compounds are attracting much attention in the field of organic functional materials science. While 1,7-PDI regioisomers are synthetically accessible in pure form, it is still a challenging task to obtain 1,6-regioisomers in pure form. Ground state equilibrium geometries were optimized using the B3LYP functional with triple-ζ quality TZVP basis set. Introduction of either bromine or amino substituent groups at 1,6(7)-positions distorts the planarity of perylene core. Core twisting is larger for the derivatives substituted at 1,6-positions. For computing singlet vertical excitation energies, global hybrids B3LYP, PBE0 and range-separated hybrid CAM-B3LYP density functionals tested. B3LYP computed the most accurate excitation energies against experimental absorption maximum (λmax), with a mean absolute deviation (MAD) of 0.050 eV when solvent effects included. N-alkyl substituents at the bay positions shift the absorption maxima towards the ∼700 nm region. Red shifting is more efficient with 1,7-substitution, while 1,6-amino substituted PDIs display an additional absorption peak resulting from HOMO-1 to LUMO electronic transition appearing as extension of lowest energy absorption band and covers a broader region of visible spectrum. Such electronic transition is hardly detectable for 1,7-regioisomers. Calculations reveal that amino substituted 1,6-regioisomers display lower-lying HOMOs compared to the respective 1,7-regioisomers. This observation is in line with the NBO analysis, suggesting higher contribution of side groups to HOMO levels in 1,7-regioisomers. Plotted frontier molecular orbital isodensity surfaces reveal that electron density distribution is affected markedly from the position of amino substituents on PDI core.

A Cost‐Effective D‐A‐D Type Hole‐Transport Material Enabling 20% Efficiency Inverted Perovskite Solar Cells†

Main observation and conclusionHigh‐performance, cost‐effective hole‐transport materials (HTMs) are greatly desired for the commercialization of perovskite solar cells (PVSCs). Herein, two new HTMs, TPA‐FO and TPA‐PDO, are devised and synthesized, which have a donor‐acceptor‐donor (D‐A‐D) type molecule design featuring carbonyl group‐functionalized arenes as the acceptor (A) units. The carbonyl group at the central core of HTMs can not only tune frontier molecular orbital (FMO) energy levels and surface wettability, but also can enable efficient surface passivation effects, resulting in reduced recombination loss. When employed as HTMs in inverted PVSCs without using dopant, TPA‐FO with one carbonyl group yields a high power conversion efficiency (PCE) of 20.24%, which is among the highest values reported in the inverted PVSCs with dopant‐free HTMs. More importantly, the facile one‐step synthetic process enables a low cost of 30 USD g–1 for TPA‐FO, much cheaper than the most studied HTMs used for high‐efficiency dopant‐free PVSCs. These results demonstrate the potential of D‐A‐D type molecules with carbonyl group‐functionalized arene core in developing the low‐cost dopant‐free HTMs toward highly efficient PVSCs.

Physical properties and biological activity of methyldopa drug carrier cellulose derivatives. Theoretical study

The complete computational study of the methyldopa drug and its derivatives prodrug 1-4(methyldopa-cellulose (Ce), methyldopa-carboxymethyl cellulose(CMC), methyldopa-maleic anhydride cellulose (MAC)and methyldopa-hydroxypropyl cellulose(HPC)) was performed by Density Function theory method with the Becker’s three parameter hybrid functional (B3LYP) functional and 6-31G++ (d, p) basis set using Gaussian 09 program. The Density Function theory (DFT) DFT method is used to calculate the optimal molecular structure, vibrational spectra, highest occupied molecular orbital energies (HOMO), lowest unoccupied molecular orbital energies (LUMO), electronic properties (total energy, dipole moment, electronegativity, chemical hardness and softness), biological activity, and molecular surfaces. Using the reaction coordinate method to quantify the energy enthalpy and activation energy of O-R bond rupture. The result shows the derivatives that are hoped to have preference in their use as carriers are (methyldopa-Ce) and (methyldopa-MAC), which gave the drug acid as a product of the O-R bond breaking process in an irreversible reaction.

New Amine/Phenylglycedyl Ether Adducts for Mild Steel Protection in 1 M HCl: Experimental and Computational Study

AbstractThe key objective of this study is to ascertain the effect of structure and increased molecular size on the corrosion inhibition potential of two synthesized amines, when compared to their precursor compounds. The product amines were N‐(2‐hydroxy‐3‐phenoxy) ethanolamine (NHPE), N,N−Di‐(2‐hydroxy‐3‐phenoxypropyl) ethanolamine (NNHPE) synthesized from monoethanolamine (MEA) and phenyl glycidyl ether (PGE) as starting materials. Both starting and product amines were characterized using FTIR spectroscopy. The corrosion inhibition potentials were assessed using experimental and quantum theoretical modeling and calculations. Some key electronic properties such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, gap energy, dipole moment and surface area, were calculated and discussed. The various approaches adopted in this study were in reasonable agreement and the following average inhibition efficiency trend was obtained: NNHPE (75.7 %)&gt;NHPE (68.3 %)&gt;PGE (64.2) &gt;MEA (61.0).

Synthesis, X-ray crystallography, vibrational spectroscopy, thermal and DFT studies of (E)-6-(4-methylstyryl)-4,5-dihydropyridazin-3(2H)-one

A novel pyridazin-3(2H)-one derivative, (E)-6-(4-methylstyryl)-4,5-dihydropyridazin-3(2H)-one (3) has been synthesized and characterized by FT-IR, UV–vis, 1H- and 13C NMR, TGA/DTA thermal analysis and single-crystal X-ray diffraction. Furthermore, the molecular geometry, vibrational frequencies, electronic absorption spectra, chemical shift values, HOMO-LUMO analysis, frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) surface map of the title compound were calculated using DFT/B3LYP method with 6–31+G (d,p) basis set. A comparison among the experimental and calculated results indicates that the vibrational frequencies, maximum electronic absorption wavelengths and chemical shift values are in a good agreement with each other. The intermolecular interactions in the crystal structure were investigated using Hirshfeld surface analysis. TGA/DTA thermal analysis revealed that the title compound is thermostable to its melting point.

Boron nitride-incorporated NiOx as a hole transport material for high-performance p-i-n planar perovskite solar cells

In recent years, organo-metal halide perovskite and p-i-n planar perovskite solar cells (PSCs) based on it have received tremendous attention due to their high efficiency close to silicon, low temperature process, and ease of cost-effective large-scale manufacturing. However, p-i-n planar PSCs have low fill factor and low current density due to poor interface properties, resulting in low performance. In this work, to solve these problems, we introduce boron nitride (BN) as an interface modifier and demonstrate that the BN incorporated NiOx (NiO:BN) is effectively working as hole transport layer of p-i-n planar PSCs. The NiO:BN hole transport layer (HTL) has a deep energy level of highest occupied molecular orbital (HOMO) and smooth surface compared to pristine NiOx, which provide the better energy level alignment and better interface contact between NiO:BN HTL and perovskite, improving charge extraction and transportation and inhibiting recombination of charge. As a result, NiO:BN based p-i-n planar PSCs represent an improved power conversion efficiency of 20.74% and long-term stability in ambient air for 60 days (maintained over 84% of their initial PCE). Therefore, it can be suggested that the NiO:BN HTL is a promising alternative HTL for high performance p-i-n planar PSCs.