Mean First-order Hyperpolarizability Research Articles

Density Functional Theory and Ab Initio Hartree-Fock Computational Study of 2-[1-Acetyl-3-Methyl-4,5-Dihydro-1H-1,2,4-Triazol-5-One-4-Yl]-Phenoxyacetic Acide

In the present theoretical study, the 2-[1-acetyl-3-methyl-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl]-phenoxyacetic acide was optimized by B3PW91 and HF methods 6-311+G (d.p) basis set using the Gaussian G09W program. The molecular structure, HOMO and LUMO energy analysis, electronic transitions, total static dipole moment, the mean polarizability, the anisotropy of the polarizability, the mean first-order hyperpolarizability, electronegativity, chemical hardness, molecular electrostatic potential maps (MEP) and Mulliken charges of 2-[1-acetyl-3-methyl-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl]-phenoxyacetic acide molecule have been investigated by using B3PW91 and HF methods with the 6-311+G (d, p) basis set. The calculated IR data of titled compound were calculated in gas phase by using of 6311+G (d, p) basis sets of B3PW91 and HF methods and are multiplied with appropriate adjustment factors. Theoretical infrared spectrums are formed from the data obtained according to B3PW91 method. In the identification of calculated IR data was used the veda4f program. 1H-NMR and 13C-NMR spectral data values were calculated according to the method of GIAO using the program package Gaussian G09W Software. Experimental data were obtained from the literature. Experimental and theoretical values were inserted into the graphic according to equitation of δ exp=a+b. δ calc. The standard error values were found via SigmaPlot program with regression coefficient of a and b constants. In addition, in vitro antioxidant properties of this compound was investigated.

Insights into solvent effects on molecular properties, physicochemical parameters, and NLO behavior of brinzolamide, a bioactive sulfonamide: A computational study

In this study, quantum chemical calculations performed on brinzolamide (BZ), a sulfonamide derivative widely used as an antibacterial and antifungal drug, are presented. The molecular geometry optimizations of BZ were calculated by using both B3LYP functional and HF method with the 6-31G (d, p) basis set via Gaussian software. Since solvent phase behaviors are extremely important especially for drug molecules, calculations were renewed for BZ in ten different solvent environments. Universal solvation model SMD (Solvent Model based on Density) was utilized for solvent phase simulations. Mulliken and natural atomic charges, frontier molecular orbital (FMO) energies, quantum chemical descriptors were studied in detail according to solvent and method variation. In addition, the partition coefficient (logPow) value, which is an important parameter for the activity of the drug candidates, was theoretically estimated according to the relevant formula through the computed values for the water and 1-octanol phases for each methodology. The slightly lipophilic character of the BZ molecule was supported by the obtained values and the molecular lipophilicity potential map prepared by means of Molinspiration Galaxy 3D Structure Generator v2018.01 beta program. In the nonlinear optical (NLO) property analysis, dipole moment (μtot), mean polarizability (αtot), anisotropic polarizability (Δα), and mean first-order hyperpolarizability (βtot) values of BZ and the solvent effect on these values have been reported. Last, the interaction energies between donor and acceptor orbitals were calculated by the analysis of natural bond orbitals, and the obtained results were summarized.

Design, Synthesis, DFT, TD-DFT/PCM Calculations, and Molecular Docking Studies on the Anti-COVID-19, and Anti-SARS Activities of Some New Bis-Thiazoles and Bis-Thiadiazole

A novel synthesis of bis(thiazoles) and bis(thiadiazole), each connected to a thienothiophene moiety, is described. The DFT calculations support the favored synthesis of one of the anticipated bis(thiazole) regioisomers. The B3LYP/6-311G** level of theory was used to optimize quantum mechanical calculations of geometrical characteristics and energy of new compounds under study. The electronic absorption of the new compounds in ethanol solvent was handled and finished using time-dependent-density functional theory (TD-DFT) at the B3LYP/6-31G(d,p) level with the addition of the polarizable continuum solvation technique TD-DFT/PCM. The permissible singlet transitions are identified, and their involvements in the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) are described. Natural bond orbital (NBO) analysis was used to investigate hyper conjugative partnerships, molecular stability, and bond strength. Mean polarizability, total static dipole moment, anisotropy of polarizability, and mean first-order hyperpolarizability have all been computed. The results reveal that the compounds are promising contenders for non-linear optical materials. The molecular docking mechanism between ligands 8a–8c and COVID-19/5epw or SARS/5wrg receptors was done to explore the binding modes of these compounds at the active sites. Molecular docking results have shown that the compounds 8a–8c can be considered as a potential agent against COVID-19/5epw and SARS/5wrg receptors.

Investigation of Theoretical and Experimentical Properties of 2-[3-(n-Propyl)-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl]-Phenoxyacetic Acide

In the present study, 2-[3-(n-propyl)-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl]-phenoxyacetic acide was optimized by using B3LYP/6-311+G(d,p) basis set. Firstly, IR data of the compound were calculated in gas phase by using of 6-311+G(d,p) basis set of B3LYP method and are multiplied with appropriate adjustment factors. Theoretical infrared spectrums are formed from the data obtained according to B3LYP method. In the identification of calculated IR data was used the veda4f program. Then, 1H-NMR and 13C-NMR spectral data values were calculated according to the method of GIAO using the program package Gaussian G09W Software. Experimental data were obtained from the literature. Experimental and theoretical values were inserted into the graphic according to equitation of δexp=a+b. δ calc. The standard error values were found via SigmaPlot program with regression coefficient of a and b constants. Furthermore, molecular structure, HOMO and LUMO energy analysis, electronic transitions, total static dipol moment (μ), the mean polarizability (), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (), electronegativity (), hardness (), molecular electrostatic potential maps (MEP), and Mulliken charges of 2-[3-(n-propyl)-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl]-phenoxyacetic acide have been investigated by using B3LYP level with the 6-311+G(d,p) basis set.

Spectroscopic studies, density functional theory calculations, non-linear optical properties, biological activity of 1-hydroxy-4-((4-(N-(pyrimidin-2-yl)sulfamoyl)phenyl)diazenyl)-2-naphthoic acid and its chelates with Nickel (II), Copper (II), Zinc (II) and Palladium (II) metal ions

Novel Nickel (II), Copper (II), Zinc (II) and Palladium (II) chelates with 1‑hydroxy-4-((4-(N-(pyrimidin-2-yl)sulfamoyl)phenyl)diazenyl)-2-naphthoic acid (H3L) have been produced and clarified using several physicochemical techniques. Quantum mechanical calculations of energies, geometries were achieved by using the density functional theory with Becke's three parameter exchange functional, the Lee_Yang_Parr correlation functional (B3LYP/GEN) combined with 6.311 G (d,p) and LANL2DZ basis sets. The analyses of Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) have been used to justify the charge transfer within the ligand and its chelates. The considered small energy gap between Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies expressions that the charge transfer occurs within the ligand and its chelates. The results show that the azo dye ligand exists in two tautomeric structures, the first structure (H3L), the sulphonamide (SO2NH), while the second one, the sulphonamide group in enolic form (H2L-OH). The H2L-OH tautomer has energy of 12.93 kcal/mol higher than that of H3L. The structure of H3L was found to be the most stable and used as the ligand in this study. The bond lengths of Ni(II) ion with the donating sites of the ligand in Ni-(H2L)2 chelate suggest a distorted octahedral geometry, Cu2-(L) chelate, suggests a highly distorted tetrahedral geometry, Zn-(HL) chelate displays a distorted octahedral geometry, Pd-(H2L) chelate approves a distorted square planar geometry around its own central metal ion. Geometrical parameters, molecular electrostatic potential maps and total electron densities analyses of the ligand and its chelates have been carried out. Molecular stability, hyper conjugative interactions, intramolecular charge transfer and bond strength have been examined by applying of natural bond orbital (NBO) analysis. Total static dipole moment, mean polarizability, anisotropy of the polarizability, mean first-order hyperpolarizability have been also achieved. From the molecular hyperpolarizability (˂β˃), The computed (˂β˃) values show that for the ligand (H3L) and its Ni-(H2L)2, Cu2-(L), Zn-(HL) and Pd-(H2L) are ~23, ~70, ~44, ~132 and ~38 times greater than that of Urea, indicating all the studied ligand and its chelates reveal significant polarizability and first-order hyperpolarizability and are predicted to be successful for Non-Linear Optical (NLO) materials. The analyses of the chelates indicate that the Zn(II) and Pd(II) form 1:1, Ni(II) form 1:2 while Cu(II) ion form 2:1 (M:L) and non-electrolytic behavior of chelates indicate the absence of counter ion. Ni-(H2L)2 complex had zero antibacterial activity against E. coli while its activity is higher than the azo dye against Staphylococcus aureus. Pd-H2L complex had almost the same activity as the azo dye against both types of bacteria. The higher activity of Zn-HL and Cu2-L complexes can be explained by their chelation.

Synthesis, characterization, NLO properties, antimicrobial, CT-DNA binding and DFT modeling of Ni(II), Pd(II), Pt(II), Mo(IV) and Ru(I) complexes with NOS Schiff base

Thermal reaction of Ni(NO3)2.6H2O, PdCl2, PtCl2, Mo(CO)6 and Ru3(CO)12 with the prepared Schiff base ligand N-(2-hydroxy-1-naphthylidene)-2-aminothiophenol (H2L) resulted in the formation of the five complexes; [Ni(HL)2], 1; [Pt(H2L)Cl2], 2; [Pd2(HL)2Cl2], 3; [Mo(O2)(H2L)], 4; and [Ru(CO)3(HL)], 5. The studied compounds were characterized using different spectroscopic techniques (IR, 1H NMR, mass) elemental analyses, magnetic measurement, molar conductance, and thermal analysis. The kinetic and thermodynamic parameters of the complexes were computed. The geometry of studied 1:1 Pt(II)-, Pd(II)- Mo(IV)- and Ru(I)- complexes and 1:2 Ni(II)- complex were investigated at the B3LYP/GENECP level of theory. The geometries of the studied complexes are non-planner as indicated from the dihedral angles between central metal ion and coordinated atoms of the ligand. DFT calculations have been also carried out to calculate the global properties; hardness (η), global softness (S) and electronegativity (χ). The mean first-order hyperpolarizability (<β>) was calculated and compared with Urea as a reference material. The results of the mean first-order hyperpolarizability (<β>) showed that the ligand and the studied complexes are excellent candidates to NLO materials. Also, the interaction of the reported compounds with calf thymus DNA (CT-DNA) by different techniques revealed that the complexes could bind to CT-DNA by intercalative mode. The binding of the reported complexes to calf thymus DNA has been investigated using fluorescence and UV–Vis absorption spectra. The results indicated a much lower binding affinity of the ligand than that of the complexes. Biological activities of the compounds have been studied.

Preparation and spectroscopic properties, density functional theory calculations and nonlinear optical properties of poly (acrylic acid-co-acrylamide)-graft-polyaniline

Poly (acrylic acid-co-acrylamide)-graft-Polyaniline was synthesized via chemical oxidation polymerization using ammonium persulphate as initiator at 40 °C under N2 atmosphere. The prepared poly (acrylic acid-co-acrylamide)-graft-Polyaniline was characterized by different analytical tools. The apparent activation energy of grafting reaction was calculated and found to be 48.7753 kJ/mol. Also, ΔH*and ΔS* as thermodynamic parameters for activation were calculated which equal to 46.4300 k J/mol. and −14.0379 J/mol. K respectively. The optimized structures of the graft (one, two and three units or ( monomer, dimer and trimer) were theoretically investigated at the B3LYP/6-311G level. The geometry of the graft are non-planar as indicated from the values of dihedral angles. The global properties of hardness, global softness and electronegativity were calculated. The calculated small energy gap between highest occupied and lowest unoccupied molecular orbital energies shows that charge transfer occurs within the graft compound. The molecular electrostatic potential for the graft was investigated. The obtained total static dipole moment, mean polarizability, anisotropy of polarizability and mean first-order hyperpolarizability (<β>) were compared with those of urea as a reference material. The results for <β> showed that the graft is excellent candidates as nonlinear optical materials.

Novel Zn(II) complexes of 1,3-diphenyl-4-(arylazo)pyrazol-5-one derivatives: Synthesis, spectroscopic properties, DFT calculations and first order nonlinear optical properties

Eight novel Zn(II) complexes with substituted 1,3-diphenyl-4-(arylazo)pyrazol-5-one (L1-L4) derivatives have been synthesized and elucidated using various physicochemical techniques. Quantum mechanical calculations of energies, geometries were done by DFT using B3LYP/GEN functional combined with 6.311G (d,p) and LAN2DZ basis sets. The analyses of HOMO and LUMO have been used to explain the charge transfer within the ligands and complexes. The calculated small energy gap between HOMO and LUMO energies shows that the charge transfer occurs within Zn(II) complexes. Geometrical parameters, molecular electrostatic potential maps (MEP) and total electron densities analyses of the ligands and their Zn complexes have been carried out. Molecular stability, hyperconjugative interactions, intramolecular charge transfer (ICT) and bond strength has been investigated by the applying of natural bond orbital (NBO) analysis. Total static dipole moment (μ), the mean polarizability (<α>), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (<β>) have been also performed. The obtained values show that Zn(II) complexes is brilliant candidate to NLO materials. The analyses of the 1:1 complexes indicate that the Zn(II) ion is five-coordinated with water molecules at axial position in case of L1, L2 and L4 whereas, six-coordinated with L3 and non-electrolytic behaviour of complexes indicates the absence of counter ion.

Synthesis, spectroscopic characterization, first order nonlinear optical properties and DFT calculations of novel Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes with 1,3-diphenyl-4-phenylazo-5-pyrazolone ligand

Novel Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) metal ions with 1,3-diphenyl-4-phenylazo-5-pyrazolone (L) have been prepared and characterized using different analytical and spectroscopic techniques. 1:1 Complexes of Mn(II), Co(II) and Zn(II) are distorted octahedral whereas Ni(II) complex is square planar and Cu(II) is distorted trigonal bipyramid. 1:2 Complexes of Mn(II), Co(II), Cu(II) and Zn(II) are distorted trigonal bipyramid whereas Ni(II) complex is distorted tetrahedral. All complexes behave as non-ionic in dimethyl formamide (DMF). The electronic structure and nonlinear optical parameters (NLO) of the complexes were investigated theoretically at the B3LYP/GEN level of theory. Molecular stability and bond strengths have been investigated by applying natural bond orbital (NBO) analysis. The geometries of the studied complexes are non-planner. DFT calculations have been also carried out to calculate the global properties; hardness (η), global softness (S) and electronegativity (χ). The calculated small energy gap between HOMO and LUMO energies shows that the charge transfer occurs within the complexes. The total static dipole moment (μtot), the mean polarizability (<α>), the anisotropy of the polarizability (Δα) and the mean first-order hyperpolarizability (<β>) were calculated and compared with urea as a reference material. The complexes show implying optical properties.

Molecular structures, spectroscopic (FT–IR, NMR, UV) studies, NBO analysis and NLO properties for tautomeric forms of 1,3-dimethyl-5-(phenylazo)-6-aminouracil by density functional method

The equilibrium geometry, nuclear magnetic resonance (NMR) and UV–Vis analysis, and vibrational frequencies for the azo and hydrazone isomers of 1,3-dimethyl-5-(phenylazo)-6-aminouracil have been performed using density functional theory (DFT/B3LYP) method with 6–311G(d,p) basis set. A detailed interpretation of the vibrational spectra has been made on the basis of the calculated potential energy distribution (PED) obtained from the Vibrational Energy Distribution Analysis (VEDA4) program. The 1H NMR chemical shifts with respect to TMS were calculated by the gauge independent atomic orbital (GIAO) method and compared with the experimental data. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Using the TD-DFT method, electronic absorption spectra in CHCl3 solvent of the title compound have been predicted, and good agreement is determined with the experimental one. The NLO properties such as mean polarizability (⟨α⟩), the anisotropy of the polarizability (⟨Δα⟩) and the mean first-order hyperpolarizability (⟨β⟩) were computed by using finite field method. The computed values of μ, α and β for the azo and hydrazone forms of the title molecule are 5.4717 and 3.8905 D, 2.7773×10−23 and 2.7598×10−23esu, and 3.4499×10–30 and 6.8504×10–30esu, respectively. The high β values and non-zero values of μ indicate that the title compound might be a good candidate for NLO material.

Synthesis, spectroscopic characterization, second and third-order nonlinear optical properties, and DFT calculations of a novel Mn(II) complex

A novel Mn(II) complex with 1,3-Thiazolidine-2,4-dicarboxylic acid and 1,10 phenanthroline has been synthesized, and its FT-IR, FT-Raman and UV–vis spectra have been recorded. Density functional theory calculations with the HSEH1PBE/6–311++G(d,p) level have been used to determine optimized molecular geometry, harmonic vibrational frequencies, electronic transitions, infrared and Raman intensities and bonding features of [Mn(tda)(phen)] complex (tda = 1,3-Thiazolidine-2,4-dicarboxylic acid; Mn = Manganese (II); phen = 1,10 phenanthroline). The assignments of vibrational modes have been performed on the basis of the weightiness of internal coordinates contributing to the vibrational frequencies calculated by HSEH1PBE method. The calculated small energy gap between HOMO and LUMO energies shows that the charge transfer occurs within Mn(II) complex. Molecular stability, hyperconjugative interactions, intramolecular charge transfer (ICT) and bond strength have been investigated by the applying of natural bond orbital (NBO) analysis. DFT calculations have been also performed to investigate total static dipole moment (μ), the mean polarizability (<α>), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (<β>), and the mean second-order hyperpolarizability (<γ>) for Mn(II) complex. The obtained values show that Mn(II) complex is an excellent candidate to NLO materials.

Calculations of Electronic Structure and Nonlinear Optical Parameters of 4-Methoxybenzaldehyde-N-Methyl-4-Stilbazolium Tosylate*

The optimized molecular geometry, vibrational frequencies, and gauge including atomic orbital (GIAO) 1H and 13C chemical shifts of 4 -methoxybenzaldehyde-N-methyl-4-stilbazolium tosylate (MBST) were calculated using density functional theory (DFT/B3LYP) and the Hartree–Fock (HF) method with the 6-311++G(d,p) basis set. Nonlinear optical (NLO) parameters [mean polarizability ( ), the anisotropy of the polarizability (Δα), and the mean firstorder hyperpolarizability ( )] of the title compound were investigated theoretically. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies of the MBST compound were calculated with the same methods and basis set. Molecular hardness (η) and electronegativity (χ) were obtained by using the HOMO and LUMO molecular orbital energies. Electronic transitions of the compound were calculated with the time-dependent DFT/B3LYP (TD-DFT/B3LYP) and HF methods. Mulliken, atomic polar tensor (APT), and natural bond orbital (NBO) charges were calculated and compared with each other.

Theoretical analysis on structural, spectroscopic, and electronic properties of some 2-aminobenzimidazole complexes by using PBE1PBE, B3LYP, and HF methods

The molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) 1H and 13C chemical shift values of ABZ-TNB [ABZ-TNB: 2-aminobenzimidazole-trinitrobenzene] and ABZ-PA [ABZ-PA: 2-aminobenzimidazole-picric acid] in the ground state were calculated by using density functionals (B3LYP and PBE1PBE) and Hartree-Fock (HF) methods with the 6–31 ++ G(d,p) basis set. Furthermore, the electronic spectrum of title complexes was calculated with the time dependent DFT levels (TD-PBE1PBE and TD-B3LYP) and HF (TD-HF) method starting from the ground state geometry optimized in the gas phase. A detailed assignment of vibrational spectra was made on the basis of the calculated potential energy distribution (PED). Total static dipole moment (μ), the mean polarizability (〈α〉), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (〈β〉), highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, chemical hardness (η) and electronegativity (χ) of ABZ-TNB and ABZ-PA complexes were also investigated with quantum chemical calculations. Additionally, data obtained from quantum chemical calculations were compared with the experimental ones.

1-Pentamethylbenzyl-3-nbuthylbenzimidazolesilver(I)bromide complex: Synthesis, characterization and DFT calculations

A novel NHC complex of silver(I) ion, 1-pentamethylbenzyl-3-nbuthylbenzimidazolesilver(I)bromide, was prepared and fully characterized by single crystal X-ray structure determination. FT-IR, NMR and UV–vis spectroscopies were employed to investigate the electronic transition behaviors of the complex. Additionally, the molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) 1H and 13C chemical shift and electronic transition values of silver(I) complex were calculated by using density functional theory levels (B3LYP and PBE1PBE) with LANL2DZ basis set. Also, the vibrational frequencies were supported on the basis of the potential energy distribution (PED) analysis calculated for PBE1PBE level. We were also investigated total static dipole moment (μ), the mean polarizability (〈α〉), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (〈β〉) of the title complex. Natural bond orbital (NBO) analysis was performed to determine the presence of hyperconjugative interactions, and charge distributions.

SPECTROSCOPIC STUDY, NLO PROPERTIES AND HOMO–LUMO ANALYSIS ON DIFFERENT DONOR AND ACCEPTOR SUBSTITUENTS OF THIAZOLYLAZOPYRIMIDINE CHROMOPHORES

The molecular geometry optimization, vibrational frequencies and gauge including atomic orbital (GIAO) 1H and 13C chemical shift values of thiazolylazopyrimidine chromophores have been investigated by using density functional theories (DFT/B3LYP, PBE1PBE and BHand-HLYP) and Hartree–Fock (HF) methods with 6–31++G(d,p) basis set. The computed IR and NMR spectra are used to determine the types of the experimental bands observed. Also, the vibrational frequencies are supported on the basis of the potential energy distribution (PED) analysis calculated by using PBE1PBE method. The UV-vis spectrum has been obtained by TD-DFT and TD-HF methods. Total static dipole moment (μ), the mean polarizability (〈α〉), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (〈β〉), highest occupied molecular orbital (HOMO), and lowest occupied molecular orbital (LUMO) energies of thiazolylazopyrimidine chromophores also have been investigated with quantum chemical calculations. Obtained nonlinear optical (NLO) parameters are compared with experimental ones. Additionally, the molecular hardness (η) and electronegativity (χ) parameters have been obtained by using the frontier molecular orbital energies. Obtained data from thiazolylazopyrimidine chromophores are important for associating the experimental and theoretical spectra with molecular structure and their properties.