Molecular Orbital Parameters Research Articles

A Quantum Chemical Study on the Enormously Large Nonlinear Optical Response of Doped Endohedral Superalkali Na2F and Superhalogens MF4 (M = B, Al) with CNT (C56H16) Cage

AbstractIn the present communication, the interaction of single‐wall carbon nanotubes (SWCNTs) CNT (C56H16) with endohedral doped superhalogens (MF4:M = B, Al) placed outside of CNT cage and superalkali (Na2F) placed inside the cage has been studied by using a combination of DFT/B3LYP method and 6–311G(d, p) basis set. The geometry and stability of MF4@CNT‐Li2F have been studied using optimization parameters, highest occupied molecular orbit (HOMO), lowest unoccupied molecular orbital (LUMO), vibration frequencies, and thermodynamic parameters of absorption reactions. The quantum theory in atoms in molecules (QTAIM) analysis is used to analyze the nature of interactions between MF4 (M = B, Al) and Na2F@CNT. Several electronic parameters are computed by using HOMO–LUMO energy. The dipole moment, polarizability, hyperpolarizability, order parameters, anisotropic polarizability, and molar refractivity of MF4@CNT‐Li2F (M = Al, B) are used to calculate the nonlinear optical parameters (MR). The NBO analysis is used to calculate the transfer of charge to stabilized system. The calculated hyperpolarizability of Na2F@CNT‐BF4/Na2F@CNT‐AlF4 is nearly 81 times that of reference material urea (40 a.u.). The intramolecular charge transfer (ICT) moment of π electron cloud is responsible for the nonlinear optical behavior of the system.

Molecular Orbital Properties and Insulation Characteristics of Flaxseed Oil

This study aims to analyze the molecular orbital parameters of flaxseed oil (linum usitatissimum) and to measure the AC breakdown voltages at different electrode gaps with various rate of rises. AC breakdown voltages of flaxseed oil are measured at 1.0 and 2.5 mm electrode settings with 0.5 kV/s, 2.0 kV/s and 3.0 kV/s rate of rises, adhering to IEC and IEEE standards. UV-VIS (Ultraviolet–Visible) and FT-IR (Fourier Transform-Infrared) measurement tests carried out after breakdown voltage measurements reveals that the molecular structure of the oil remains stable against electrical discharges. The compounds of flaxseed oil are analyzed using GC-MS and it is determined that the oil mainly consists of seven triglycerides in accordance with the literature. In order to better understand the electrical behavior of these triglycerides, molecular orbital properties such as ionization potential, electron affinity and electron energy gap are analyzed employing Density Functional Theory (DFT) using B3LYP/6-311 + G(d,p) and B3PW91/6-311 + G(d,p) basis sets. The advantages of flaxseed oil such as AC dielectric strength, stability against breakdown mechanism, homogeneous molecular electrical characteristics of its compounds and antioxidant content make this oil as one of the potential natural ester alternatives to mineral oils in the power system industry.

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.

Synthesis of New Derivatives of Benzylidinemalononitrile and Ethyl 2-Cyano-3-phenylacrylate: In Silico Anticancer Evaluation.

In this study, microwave-assisted Knoevenagel condensation was used to produce two novel series of derivatives (1-6) from benzylidenemalononitrile and ethyl 2-cyano-3-phenylacrylate. The synthesized compounds were characterized using Fourier transform infrared (FT-IR) and 1H NMR spectroscopies. The pharmacodynamics, toxicity profiles, and biological activities of the compounds were evaluated through an in silico study using prediction of activity spectra for substances (PASS) and Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) studies. According to the PASS prediction results, compounds 1-6 showed greater antineoplastic potency for breast cancer than other types of cancer. Molecular docking was employed to investigate the binding mode and interaction sites of the derivatives (1-6) with three human cancer targets (HER2, EGFR, and human FPPS), and the protein-ligand interactions of these derivatives were compared to those reference standards Tyrphostin 1 (AG9) and Tyrphostin 23 (A23). Compound 3 showed a stronger effect on two cell lines (HER2 and FPPS) than the reference drugs. A 20 ns molecular dynamics (MD) simulation was also conducted to examine the ligand's behavior at the active binding site of the modeled protein, utilizing the lowest docking energy obtained from the molecular docking study. Enthalpies (ΔH), Gibbs free energies (ΔG), entropies (ΔS), and frontier molecular orbital parameters (highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap, hardness, and softness) were calculated to confirm the thermodynamic stability of all derivatives. The consistent results obtained from the in silico studies suggest that compound 3 has potential as a new anticancer and antiparasitic drug. Further research is required to validate its efficacy.

Investigation of nonlinear optical responses of organic derivative of imidazole: imidazole-2-carboxaldehyde

Abstract In the present work, we explored the nonlinear optical properties of imidazole-2-carboxaldehyde, which is an aromatic derivative of imidazole. Optimization has been performed for imidazole-2-carboxaldehyde using density functional theory with a B3LYP/6-311G basis set. To check the possible charge transfer, Mulliken charge analysis and molecular electrostatic potential analysis was performed. The chemical reactivity of the probe molecule was investigated by calculating different frontier molecular orbital parameters such that energy gap, ionization potential, electron affinity, chemical potential, electronegativity, softness, and hardness. Raman, Fourier transform infrared, and nuclear magnetic resonance analysis was also performed to study vibrational properties and UV–vis was performed to study the electronic properties of the compound. A high value of dipole moment (μ total), polarizability (α), first-order hyperpolarizability (β), and Raman activity validates the NLO behavior of the compound. Thus, the performed computational study validates a strong candidature of imidazole-2-carboxaldehyde to be used as a non-linear optically active material in the future.

Metal oxide decorated polyaniline based multifunctional nanocomposites: An experimental and theoretical approach

When combined with metal oxide nanoparticles, conducting polymers may result in unique or synergistic effects in their properties. Fe/Mn/CuO/PANI (FMC/PANI) based nanocomposites (NCs) were explored for five different novel applications. FTIR, UV–visible, XRD, Raman, and FESEM methods were used to identify the NCs. The anti-corrosive, photocatalytic, magnetic, antibacterial, and electrical properties were investigated by experimental and theoretical (DFT) methods. The computational technique was used for frequency, geometry optimization, and energy study. Different thermodynamic, kinetic, and molecular orbital parameters were investigated by the DFT study for the NCs. The anti-corrosive, photocatalytic, antibacterial, electrical, and magnetic properties of NCs were investigated at different concentrations. The FMC/PANI NCs show a maximum of 85 ± 0.2% CIE for MS in 1.0 M HCl solution. The magnetic study proves the paramagnetic nature of NCs. The photocatalytic activity of FMC/PANI NCs was investigated against MO dye under UV light. The antibacterial property of FMC nanoparticles (NPs) was investigated against gram-positive and gram-negative bacterial strains, that is, B. subtilis and E. coli, respectively. The ZOI was compared with six standard antibiotics and found to be comparable with common antibiotics. The FMC/PANI-based NCs were proven to be perfect photocatalytic, magnetic, antibacterial, electrical conductors, and anti-corrosive agents.

Deeper insights into the density functional theory of structural, optical, and photoelectrical properties using 5-[(4-oxo-4H-chromen-3-yl) methylidene]-4-oxo (thioxo)-6-thioxo-2-sulfido-1, 3, 2-diazaphosphinanes

The structure–activity relationship studied by DFT calculations and contacted with practical antimicrobial results for compounds 1–4 is discussed in detail. In light of this compounds 1–4 have been studied by using DFT/B3LYB/6-311++G (d,p) at the level of theory, the geometrical parameters, bond lengths and bond angles have been discussed. The results of quantum mechanical calculations showed that the presence of phosphorus and sulfur atoms changed the planarity of the parent compound 1 by the range from − 11 to 125°. The electronic parameter and dipole moment of these compounds in the ground state theoretically is analyzed by computing HOMO and LUMO pictures. Using frontier molecular orbital analysis, various spectroscopic and quantum chemical parameters are evaluated. Besides, absorption energies, oscillator strength, and electronic transitions of 1,3,2-diazaphosphinines 1–4 molecules have been derived at TD-DFT/CAM-B3LYP/6-311++G (d,p) computations utilizing, then the CAM-B3LYP method is “the Coulomb-attenuating method bases” set studied the electronic absorption spectra theoretically in the gas phase (TD-DFT) with the polarized split-valence 6-311++G (d, p) basis sets, in addition, the corrected linear response polarizable continuum model and measured experimentally in methanol and cyclohexane indicate a good agreement with the observed spectra (practically) in UV–Vis spectra. The molecular electrostatic potential surfaces plots have been computed to understand reactivity points.

Molecular characteristics of 1-benzhydrylazetidin-3-ol by time-dependent density functional theory analysis

1-benzhydrylazetidin-3-ol (BA3) molecule was characterized by its experimental UV–Visible (200–400 nm) spectrum in a solution of chloroform and simulated spectrum using time-dependent density functional theory (TD-DFT). The computations were made using density functional theory employing B3LYP exchange–correlation functional in conjunction with the 6–311++G(d,p) basis set. Good agreement was observed between measured and computed quantities corresponding to structure parameters and UV–Visible spectrum. The chemical reactivity of the molecule was identified with the help of frontier molecular orbital (FMO) parameters. The non-linear optical (NLO) behavior of the molecule was studied by computing the values of hyperpolarizability (βt), polarizability (αt), and dipole moment (μt). NBO analysis has been used to examine the molecule's stability as a result of hyper-conjugative interactions and charge delocalization. According to NBO analysis, the title molecule has O-H• • • N and C-H• • •N bifurcated hydrogen bonds, which is compatible with the result of the molecular structure study. It is evident from the computed HOMO and LUMO energies that charge transfer takes place within the molecule. The NLO parameters also confirm these findings. Thermodynamic parameters were also computed for this molecule.

Anti-hypertensive properties of 2-[N-(4-methylbenzenesulfonyl)-1-phenylformamido]-n-(4-nitrophenyl)-3-phenylpropenamide: Experimental and theoretical studies

Experimental and theoretical investigation of the anti-hypertensive activity of novel 2-[N-(4-methylbenzenesulfonyl)-1-phenylformamido]-N-(4-nitrophenyl)-3-phenylpropenamide (MBPNPP) was carried out. The experimental approach followed the dietary induction of spontaneously hypertensive adult male Wistar rats (SHRs) using 66% w/v d-fructose and the angiotensin I-converting enzyme (ACE) inhibitory activity assay while the theoretical study was achieved using DFT calculations and molecular docking against hypertension responsive proteins. The Becke-3-Paramater-Lee-Yang-Parr (B3LYP) functional/6–311G++(d,p) basis set was adopted. The molecular electronic properties such as the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and other chemical reactivity parameters were evaluated to bring to light, the reactivity and stabilization mechanisms of MBPNPP. The highest daily oral dose of MBPNPP (10 mg/kg) significantly prevented increase in systolic blood pressure (SBP) comparable to positive and normal control groups receiving captopril (10 mg/kg/day) and distilled water (5 ml/kg) ad libitum respectively from 167.23 (negative control) to 124.50 and 120.17 (positive control). Molecular simulation was also carried out with target proteins; 2ydm, 2 × 8Y, and 3ZQZ, and the theoretical data expresses a much plausible therapeutic significance towards the control of hypertension. The frontier orbital energy gap of 3.066 eV was an indicator that the charge transfer interaction occurred within the molecule and indicates high chemical reactivity. Relative to the reference drug, Spironolactone, the compound under study showed a significant binding affinity of -9.0 kcal/mol, -8.3 kcal/mol, and -7.9 kcal/mol with the target proteins and better protein-ligand hydrogen bond interactions. The data gathered from the experimental and theoretical analysis including the docking scores showed excellent anti-hypertensive activity by MBPNPP.

Experimental and DFT Quantum Chemical Studies on Structural, Vibrational and Molecular Properties of Some Substituted 4-Phenylphenols

Fourier Transform infrared spectra (4000–400 cm−1) and Fourier Transform Raman spectra (4000–50 cm−1) were recorded for 2-chloro-4-phenylphenol (CP); 2-nitro-4-phenylphenol (NP); and 2-amino-4-phenylphenol (AP). 1H and 13C NMR spectra, along with UV-Vis spectra of the three samples were also measured. Quantum chemical calculations, at the level of DFT/B3LYP/6-311++G(d,p) theory were implemented to study their ground state geometry, vibrational wave numbers, infrared and Raman intensities, 1H and 13C NMR spectra, frontier molecular orbital parameters, NLO behavior, NBO properties, thermodynamic quantities, rotational constants and MESP behavior. TD-DFT variant was employed to simulate electronic transitions of these molecules. Observed and calculated vibrational frequencies agreed with an rms error 7.44, 8.98 and 6.97 cm−1, the corresponding RMSD values being 7.09, 9.39 and 6.59 cm−1 for CP, NP and AP, respectively. Experimental chemical shifts concurred, with their theoretical counterparts, with RMSD value, 0.19, 0.29 and 0.56 ppm for 1H NMR; and 6.34, 6.28 and 5.39 ppm for 13C NMR, respectively, in CP, NP and AP. This kind of agreement was also true for absorption maxima (λ max) of their electronic transitions in solution form. Frontier molecular orbitals were found useful to understand origin of electronic transition maxima and chemical reactivity of the three molecules which was supported by NBO analyses. The computations showed that the three molecules were potentially good for developing NLO materials. MESP investigations showed that the most reactive sites are at oxygen atoms in the three molecules. Moreover, we also made an attempt to understand the effect of deactivating (Cl, NO2) and activating (NH2) groups on certain properties of the three molecules. Presence of intra-molecular hydrogen bond was predicted in CP, NP and AP.

Computational, Investigational Explorations on Structural, Electro-Optic Behavior of Pelargonidin Organic Colorant for TiO2 Based DSSCs

In an expedition for green-energy generation and to lower the cost per watt of solar energy, environmentally friendly biotic colorants were separated from Tectona grandis seeds. The prime colorant in the extract is pelargonidin which sensitizes titanium dioxide (TiO2)-based photo anodes. The pelargonidin-sensitized TiO2 nanomaterials endured structural, photosensitive, spectral and current-voltage interpretations. Frontier molecular orbital analysis, physicochemical and electronic parameter computation, UV–visible and DOS spectral analysis, van der Waals prediction and molecular electrostatic potential map were performed theoretically with Gaussian tools, and IR symmetry response was computed using the crystal maker software package. The pelargonidin-sensitized TiO2-created dye-sensitized solar cells which exhibited capable solar light energy to photon conversion proficiency. For comparative purposes, the commercial P25 Degussa TiO2-based DSSC was also fabricated and its proficiency was analyzed. The commercial TiO2 exhibited 57 % higher proficiency in comparison to the sol-gel-derived TiO2-based DSSC.

The study of Letrozole adsorption upon CCT nanotube: A DFT/TD-DFT and spectroscopic (excited states and UV/Vis)

In this research, the geometric structure of LTZ and CCT (5,0) was optimized with B3LYP/6-31G* method using the Gaussian 09W program package to investigate the weak interaction of Letrozole (LTZ) and carbon carbon nanotube (CCT). According to the calculation of the release energy, it was found that the drug delivery process is desirable. Also, the structural properties of the title compounds were assessed by thermodynamic and frontier molecular orbital (FMO) parameters. In this study, a series of measures have been performed to detect changes in drug loading properties and non-bonding interactions between the LTZ and CCT (5,0) nanotube. The non-bonding interaction effects of LTZ and CCT over the electronic properties were also evaluated and argued. The research is based on the fact that studies can help to understand the interaction between the LTZ drug and CCT (5,0) nanotube and the development of CCT-based drug release systems. This research aimed to determine variations in electronic properties of anticancer LTZ drug in presences CCT. Then, the reactivity and stability behavior of LTZ drug and on CCT to be examined by density functional theory (DFT). Then, frontier molecular orbital (FMO) and noncovalent interaction (NCI) analyses were performed, which decrease in reactivity described increase in the stability of LTZ drug.

Computational analysis of substituent effect on indole derivatives as potential antibacterial agents

In recent years, indole derivatives have gained attention as an important class of antimicrobial drugs. The modification of 1,3,4-oxadiazole and 1,2,4-triazole, which are known bioactive agents, was carried out with indole. The resulting compounds namely 3-(1H-indole-3yl)-5-((2-((5-phenyl-1,3,4-oxadiazole-2-yl)thio)ethyl)thio)-4H-1,2,4-triazole-4-amine (S) and 2-(5-(benzylthio)-4H-1,2,4-triazole-3yl)-1H-indole (B) were further investigated for their chemical reactivity with 14 different substituents at the phenyl ring using the density functional theory (DFT). The quantum chemical data used to investigate the most effective drug was based on the optimized geometries, molecular electrostatic potential maps, frontier molecular orbital distributions, Hirschfeld charges, Mulliken charges and UV absorption parameters obtained from DFT calculations. Reduced density gradient (RDG) scatter plots and non-covalent interaction isosurfaces were obtained to visualize the intramolecular interactions in the molecules. Based on the DFT calculations, S14 (-NO2 substituted S) and B14 (-NO2 substituted B) exhibited a better chemical activity. Further, the pertinency of S14 and B14 was tested as an antibacterial agent against E. coli using molecular docking studies. The binding affinity of S14 and B14 showed significant binding with the active sites of the E. Coli macromolecule (PDB id- 2Y66). The boiled egg model was also analyzed to study the permeability and lead likeness of the molecules under investigation. From the synthetic accessibility score, the synthetic feasibility of S14 and B14 was analyzed.

Optical, structural, physical, and nuclear shielding properties, and albedo parameters of TeO2–BaO–B2O3–PbO–V2O5 glasses

In this study, glass systems were constructed according to the formula 34TeO2∙xBaO∙35B2O3∙(30-x)PbO∙1V2O5 (x=0, 5, 10, 15, 20, 30 mol%). The gamma, neutron, proton, and alpha shielding characteristics of the glasses were evaluated for nuclear security applications. The mass attenuation coefficient (MAC), half-value layer, mean free path, effective atomic number, and radiation protection efficiency (RPE) were experimentally measured in the energy range of 59.54–661.62 keV. In addition, the theoretical MAC values were determined. The exposure buildup factor, fast neutron removal cross section, mass stopping power, and projected range values for proton (H1) and alpha (He+2) particles were theoretically determined. Albedo parameters were measured for the prepared glasses at photon energy of 59.54 keV. The optical and structural properties were studied using X-ray diffraction, FT-IR Fourier transform infrared, ultraviolet–visible, and electron paramagnetic resonance spectroscopy. The glass samples comprised structural units such as TeO4, TeO3, BO3, and BO4. The spin Hamiltonian parameters, g∥, g⊥, A∥, A⊥, dipolar hyperfine coupling parameter, P, and Fermi contact parameter, κ, were calculated. The molecular orbital parameters, α2, β2, and γ2, were determined by optical absorption spectroscopy. The number of bonds per unit volume in the glasses ranged between 8.763 and 9.212×1028 m−3. The most reflective compound among the glasses investigated was BaO. Good agreement was found between the theoretical and experimental MAC values. TeBaBPbV1 glass was identified as a potential candidate for use in neutron, gamma, proton, and alpha shielding.

Promising bio-active complexes of platinum(II) and palladium(II) derived from heterocyclic thiourea: Synthesis, characterization, DFT, molecular docking, and anti-cancer studies

Four Platinum(II) and Palladium(II) heterocyclic thiourea complexes have been prepared; [Pt(CPPT)2](1), [Pd(CPPT)2](2), [Pt(MPPT)2](3), and [Pd(MPPT)2](4) (Where HCPPT=1-(5-chloropyridin-2-yl)-3-phenylthiourea, HMPPT=1-(3-methylpyridin-2-yl)-3-phenylthiourea). Both the ligands and the complexes were characterized by different spectroscopic techniques including: FT-IR, 1H, 13C-{1H} NMR and Mass spectroscopy. The spectroscopic data analysis suggested that the complexes (1–4) adopt a square planar geometry with cis-configuration of platinum and trans- configuration of Palladium complexes. Antiproliferative data indicated that palladium(II) complexes exerted a potent cytotoxic activity in comparison with platinum(II) complexes. Among all tested complexes, [Pd(MPPT)2] exhibited a promising activity with an IC50 value of 10.44 and 17.7 µM against colon cancer cell lines (LoVo) and breast cancer cell lines (MCF-7) respectively. Theoretical calculations were applied to estimate the physical properties and the inhibition activity of cancer cells by docking. Gaussian 09 software with 6-311G (d, p) basis set was used for theoretical study. Furthermore, quantum chemical parameters of highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), dipole moment, energy gap and other parameters were used to evaluate the complexes activity. MGL tools and DSV software were used to test the complexes inhibitions of breast cancer by blocking the damage cells.

Corrosion inhibition behavior of expired diclofenac Sodium drug for Al 6061 alloy in aqueous media: Electrochemical, morphological, and theoretical investigations

The behavior corrosion inhibition of aluminum alloy (Al6061) in acidic (0.1 M HCl) and saline (3.5% NaCl) solutions was investigated in the absence and the presence of expired diclofenac sodium drug (DSD) as a corrosion inhibitor. The influence of temperature and was studied using electrochemical techniques. In addition, scanning electron microscopy (SEM) was used to study the surface morphology. The results showed that DSD acted as a powerful inhibitor in acidic solutions, while a moderate influence was observed with saline one. Maximum inhibition efficiency was 99.99 and 83.32% in acidic and saline solutions at 150 ppm of DSD, respectively. Corrosion current density that obtained using electrochemical technique was increased with temperature and decreased with the addition of DSD in both, acidic and saline solutions. DSD acted as a mixed-type corrosion inhibitor in acidic solution, while it affected the cathodic reaction in saline solution. Scanning electron microscopy (SEM) showed a significant surface damages in the absence of DSD. Quantum chemical theoretical studies were also addressed. Three states of DSD were considered in understanding the mechanism of inhibition. Normal, dissociated, and protonated states were optimized using Density Function Theory (DFT). Highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), energy gap (ΔE), dipole moment (µ), and other parameters were used to compare the performance of DSD states. Theoretical studies showed that the protonated state gave higher protection efficiency.

Experimental and theoretical electronic absorption spectra, optical, photoelectrical characterizations of 1, 2, 3-Thiazaphosphinine and 1, 2-Azaphospholes bearing a chromone ring: Solvatochromic effect and TD/DFT approach

Geometry, global energetic and dipole moment of the studied structures 1-4 in the ground state are calculated using the DFT/B3LYB/6-311++G (d,p) level of theory. It has been uncovered that compounds containing 1, 2, 3-thiazaphosphinine and 1, 2-azaphospholes bearing a Chromone ring structure displays noteworthy biological properties. The studied compounds 1-4 are non-planar, as indicated from the dihedral angles. Using frontier molecular orbital (FMO) analysis, various spectroscopic and quantum chemical parameters are evaluated. Besides, absorption energies, oscillator strength, and electronic transitions of 1, 2, 3-thiazaphosphinine and 1, 2-azaphospholes 1-4 molecules have been derived at TD-DFT/CAM-B3LYP/6-311++G (d, p) computations utilizing a PCM and measured in different solvents polar and non-polar experimentally in Uv-Vis spectra. The second-order perturbation interactions between donor and acceptor MOs of the ground state and the natural bond orbital (NBO) analysis show a localization and delocalization of electron density, intermolecular Charge Transfer CT character of n-π*, π-π* transitions. The calculated at the same level of theory which NLO, α, Δα and first order β were showed promising optical properties. For the understanding of reactivity points, the molecular electrostatic potential surfaces (MEPS) plots have been computed. All the calculations have been performed in the gas phase.

Structural, Spectroscopic (UV-Vis and IR), Electronic and Chemical Reactivity Studies of (3,5-Diphenyl-4,5-dihydro-1H-pyrazol-1-yl)(phenyl)methanone

The (3,5-diphenyl-4,5-dihydro-1H-pyrazol-1-yl)(phenyl)methanone (DPPPM) were synthesized by using rapid and recyclable reaction media polyethylene glycol-400 (PEG-400) and catalytic amount of acetic acid. This method gives remarkable advantages such as simple workup and a greener method by avoiding hazardous and toxic solvents. The computational calculations for title compound have been carried out by using DFT method with B3LYP hybrid functional and 6-311++G (d, p) basis set. The structural parameters like bond lengths, bond angle, and dihedral angles were obtained from the optimized molecular geometry and discussed. This structural analysis shows, the DPPPM molecule has non-planar structure and possess C1 point group symmetry. The infrared vibrational spectral bands assignments were made by correlating experimental findings with the computed data and results shows good agreement. The electronic spectral properties were explored using the time-dependent density functional theory (TD-DFT) in the gas phase and two different polarity solvents. This obtained theoretical UV-Visible absorption results are in acceptable concurrence with the UV-Visible absorption experimental results. The solvent effect on wavelength of absorption also been reported. The frontier molecular orbital, MESP and global chemical reactivity parameters for the title molecule in the gas phase were reported and discussed. Theses result shows molecule possesses good strength and stability.

Spectroscopic, quantum computational, molecular docking and biological parameters of 4-phenylbutyrophenone: a neuroleptic agent

In this work, density functional theory and vibrational spectroscopic studies are carried out to elucidate the structure, physiochemical parameters and biological behaviors of 4-phenylbutyrophenone. By using energy minimization, the optimized structure of 4-phenylbutyrophenone (4PBP) is obtained. The functional group present in the compound and its properties are obtained by FT-IR, FT-Raman and NMR methods, and it is compared with simulated scaled values along with assignments by potential energy distribution. The inter- and intramolecular charge transfer and stability of the molecule are obtained by natural bond orbital analysis. The reactive areas of the molecule are studied quantitatively and qualitatively by Fukui function analysis and molecular electrostatic potential diagram, respectively. By using frontier molecular orbital theory, the highest occupied molecular orbital, lowest unoccupied molecular orbital and other various parameters are calculated and compared with the known antipsychotic drug melperone. The electronic transition is obtained by experimental UV–Vis spectrum, and it is compared with the time-dependent DFT method with various solvents. The effect of temperature on the molecule is discussed to know the thermal stability of the molecule. The drug-likeness values of 4PBP are compared with known human drugs to confirm the same neuroleptic activities, and it confirms the drug nature of 4PBP. In addition, comparative molecular docking was analyzed with this ligand and melperone (an a typical antipsychotic) with the suitable target protein. Lipophilicity studies compared with other drugs show that this has good transport well inside the human lipid system. Molecular docking supports the neurological activity of the compound with a low binding energy value of −7.55 kcal/mol to bound easily without additional energy with the target proteins confirms 4PBP is a good neuroleptics potential candidate.

Synthesis and evaluation of molecular structure from torsional scans, study of molecular characteristics using spectroscopic and DFT methods of some thiosemicarbazones, and investigation of their anticancer activity

Synthesis of 2-((2-aminopyridin-3-yl) methylene) hydrazinecarbothioamide (APHT) was attempted. Elemental analysis and NMR spectra were used to ascertain its formation. Torsional potential energy scans for all five of its rotating bonds were made to get approximate dihedral angles. UV–Vis spectra were measured for APHT and 2-((2-aminopyridin-3-yl) methylene)-N-methylhydrazinecarbothioamide (APMHT). Their anticancer activity was determined experimentally, for human carcinoma cell lines pertaining to liver, colorectal, and lung. For both APHT and APMHT, frontier molecular orbital parameters, NLO behaviour, and NBO characteristics 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 both molecules in DMSO-d6 solvent. Frontier molecular orbitals were used to understand origin of UV–Vis spectra and chemical reactivity of the two molecules. Good agreement was found between measured and computed structure parameters. This is also true of experimental and theoretical UV–Vis spectra. The computations demonstrated that both the molecules were good for NLO applications, which was substantiated by NBO analysis. Existence of bifurcated intramolecular hydrogen bond was predicted for both APHT and APMHT.