The effect of complex formation on the static and frequency-dependent nonlinear optical properties: A combined experimental and theoretical investigation.

A novel mixed ligand Mn(II) complex of 6-Bromopyridine-2-carboxylic acid (6Brpca) and 4,4'-dimethyl-2,2'-dipyridyl has been prepared and structurally characterized using single-crystal X-ray diffraction. The spectroscopic properties were also analyzed by using FT-IR and UV-Vis spectral techniques. The coordination complexes having transition metal ions are known to have promising optical nonlinearity behavior.

α-glucosidase, docking and density functional theory studies on novel azide metal complexes.

The goal of this study is to synthesize new metal complexes containing -methyl-1-(pyridin-2-yl)methanimine and azide ligands as α-glucosidase inhibitors for Type 2 diabetes. The target complexes () were synthesized by reacting -methyl-1-(pyridin-2-yl)methanimine (L) with sodium azide in the presence of corresponding metal salts. The investigation of target protein interactions, vibrational, electronic and nonlinear optical properties for these complexes was performed by molecular docking and density functional theory studies.

Static/dynamic first and second order hyperpolarizabilities, optimized structures, IR, UV-Vis, H and C NMR spectra for effective charge transfer compounds: A DFT study.

The effective charge transfer compounds, 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium m-trifluoromethylbenzene-sulfonate (DSMFS) and 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium p-trifluoromethylbenzene-sulfonate (DSPFS), were simulated in terms of geometric structure, IR, UV-Vis, H NMR and C NMR spectra. UV-vis spectra for both molecules give two peaks at 290 and 436 nm assigned as n-π* and π-π* transitions. The HOMO-LUMO energy gap for DSMFS (2.

First and second order hyperpolarizabilities of flavonol derivatives: A density functional theory study.

In this study, seventeen flavonol derivatives (1-17) were evaluated with regard to their first- and second-order hyperpolarizability parameters. For this purpose, the molecular geometries of 1-17 were optimized by using B3LYP/6-311++G(d,p) level. Spectroscopic characterizations for 1-17 were executed through the calculations of IR, UV-vis, H NMR and C NMR spectra.

Concentration effects on optical properties, DFT, crystal characterization and α-glucosidase activity studies: Novel Zn(II) complex.

A novel Zn(II) complex of 6-ClpicH and picH was synthesized and its structure was determined by XRD technique. The detailed experimental optical susceptibility and band gap, refractive index, linear polarizability, optical and electrical conductivity parameters in various concentrations were investigated by means of the UV-Vis spectroscopic data. The optical band gap, refractive index (n), linear optical susceptibility (χ), third-order nonlinear optical susceptibility (χ), second- and third-order nonlinear optical (β and γ) parameters were examined by using DFT/M06-L and ωB97XD/6-311++G(d,p) levels.

Novel metal complexes containing 6-methylpyridine-2-carboxylic acid as potent α-glucosidase inhibitor: synthesis, crystal structures, DFT calculations, and molecular docking.

The World Health Organization (WHO) report shows that diabetes mellitus (DM) will be one of the ten deadly diseases in the near future. The best way to prevent DM is to decrease blood glucose levels and keep under control; therefore, it is important to design and synthesize the effective inhibitors that can be used in the treatment of DM disease. In this respect, a series of ten metal complexes containing 6-methylpyridine-2-carboxylic acid {[Cr(6-mpa)(HO)]·HO·NO, (1), [Mn(6-mpa)(HO)], (2), [Ni(6-mpa)(HO)]·2HO, (3), [Hg(6-mpa)(HO)], (4), [Cu(6-mpa)(Py)], (5), [Cu(6-mpa)(HO)]·HO, (6), [Zn(6-mpa)(HO)]·HO, (7), [Fe(6-mpa)], (8), [Cd(6-mpa)(HO)]·2HO, (9), and [Co(6-mpa)(HO)]·2HO, (10)} were synthesized as α-glucosidase inhibitors.

A novel series of mixed-ligand M(II) complexes containing 2,2'-bipyridyl as potent α-glucosidase inhibitor: synthesis, crystal structure, DFT calculations, and molecular docking.

Diabetes mellitus (DM) is a common degenerative disease and characterized by high blood glucose levels. Since the effective antidiabetic treatments attempt to decrease blood glucose levels, keeping glucose under control is very important. Recent studies have demonstrated that α-glucosidase inhibitor improves postprandial hyperglycemia and then reduces the risk of developing type 2 diabetes in patients.

Synthesis, antioxidant activity and SAR study of novel spiro-isatin-based Schiff bases.

A new series of 21 Schiff bases of spiro-isatin was synthesized, and their DPPH, CUPRAC and ABTS cation radical scavenging abilities were investigated for antioxidant activity. The results showed that all the synthesized compounds exhibited antioxidant activity for each assay. 5̍-(2,3-Dihydroxybenzylideneamino)spiro[[1,3] dioxolane-2,3̍-indoline]-2̍-on (5c) (IC = 4.

Copper(II) complex with 6-methylpyridine-2-carboxyclic acid: Experimental and computational study on the XRD, FT-IR and UV-Vis spectra, refractive index, band gap and NLO parameters.

Crystal structure of the synthesized copper(II) complex with 6-methylpyridine-2-carboxylic acid, [Cu(6-Mepic)·HO]·HO, was determined by XRD, FT-IR and UV-Vis spectroscopic techniques. Furthermore, the geometry optimization, harmonic vibration frequencies for the Cu(II) complex were carried out by using Density Functional Theory calculations with HSEh1PBE/6-311G(d,p)/LanL2DZ level. Electronic absorption wavelengths were obtained by using TD-DFT/HSEh1PBE/6-311G(d,p)/LanL2DZ level with CPCM model and major contributions were determined via Swizard/Chemissian program.

The effects of electronegative substituent atoms on structural, vibrational, electronic and NLO properties of some 4-nitrostilbene derivates.

Organic compounds which have one or more aromatic systems in conjugated positions show charge transfer interactions which are responsible for the non-linear properties of the compounds. A conjugated π electron system enables a pathway for the entire length of conjugation under the perturbation of an external electric field. When electron donating and withdrawing moieties are located at terminal position of conjugated backbone, nonlinear optical (NLO) properties have been increased significantly which involve the correlated and high delocalized π electron states.

Synthesis, structural and spectroscopic evaluations and nonlinear optical properties of 3,5-bis(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioic O-acid.

In this study, we report a combined experimental and theoretical study on 3,5-bis(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioic O-acid (C18H18N2O3S) molecule. The compound crystallizes in the trigonal space group R-3 with a=b=27.7151(12) Å, c=12.

Conformational, spectroscopic and nonlinear optical properties of biologically active N,N-dimethyltryptamine molecule: a theoretical study.

The effective psychoactive properties of N,N-dimethyltryptamine (DMT) known as the near-death molecule have encouraged the imagination of many research disciplines for several decades. Although there is no theoretical study, a number of paper composed by experimental techniques have been reported for DMT molecule. In this study, the molecular modeling of DMT was carried out using B3LYP and HSEh1PBE levels of density functional theory (DFT).

Effects of donor-acceptor groups on the structural and electronic properties of 4-(methoxymethyl)-6-methyl-5-nitro-2-oxo-1,2-dihydropyridine-3-carbonitrile.

Quantum chemical calculations on the geometric parameters, harmonic vibrational wavenumbers and 1H and 13C nuclear magnetic resonance (NMR) chemical shifts values of 4-(methoxymethyl)-6-methyl-5-nitro-2-oxo-1,2-dihydropyridine-3-carbonitrile [C9H9N3O4] molecule in ground state were performed using the ab initio HF and density functional theory (DFT/B3LYP) methods with 6-311++G(d,p) basis set. The results of optimized molecular structure were presented and compared with X-ray diffraction results. The theoretical vibrational frequencies and 1H and 13C NMR chemical shifts values were compared with experimental values of the investigated molecule.

Quantum chemical calculations on the geometrical, conformational, spectroscopic and nonlinear optical parameters of 5-(2-Chloroethyl)-2,4-dichloro-6-methylpyrimidine.

The optimized geometry, (1)H and (13)C NMR chemical shifts, conformational and natural bond orbital (NBO) analyses, thermodynamic parameters, molecular surfaces, Mulliken, NBO and APT charges for 5-(2-Chloroethyl)-2,4-dichloro-6-methylpyrimidine [C7H7Cl3N2] were investigated by the ab initio HF and density functional theory (DFT/B3LYP) methods with 6-311++G(d,p) basis set. The calculated structural parameters (bond lengths, bond angles and dihedral angles) and (1)H and (13)C NMR chemical shifts values are compared with experimental values of the investigated compound. The observed and the calculated values are found to be in good agreement.

The synthesis, characterization and theoretical study on nicotinic acid [1-(2,3-dihydroxyphenyl)methylidene]hydrazide.

In this study, we reported a combined experimental and theoretical study on nicotinic acid [1-(2,3-dihydroxyphenyl)methylidene]hydrazide (C13H11N3O3) molecule. The title compound was prepared and characterized by 1H and 13C FT-NMR, FT-IR and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2₁/c with a=6.

Quantum chemical characterization of N-(2-hydroxybenzylidene)acetohydrazide (HBAH): a detailed vibrational and NLO analysis.

The molecular modeling of N-(2-hydroxybenzylidene)acetohydrazide (HBAH) was carried out using B3LYP, CAMB3LYP and PBE1PBE levels of density functional theory (DFT). The molecular structure of HBAH was solved by means of IR, NMR and UV-vis spectroscopies. In order to find the stable conformers, conformational analysis was performed based on B3LYP level.

An experimental and theoretical study on the novel (Z)-1-((naphthalen-2-ylamino)methylene)naphthalen-2(1H)-one crystal.

A novel compound has been synthesized, and its structure has been characterized by IR, UV-vis, NMR and X-ray single-crystal determination techniques. The title compound crystallizes in the orthorhombic space group P212121 with a=6.2120(4)Å, b=10.

Theoretical investigation of 5-(2-acetoxyethyl)-6-methylpyrimidin-2,4-dione: conformational study, NBO and NLO analysis, molecular structure and NMR spectra.

Structural and conformational, natural bond orbital (NBO) and nonlinear optical (NLO) analysis was performed, and (1)H and (13)C NMR chemical shifts values of 5-(2-Acetoxyethyl)-6-methylpyrimidin-2,4-dione [C9H12N2O4] in the ground state were calculated by using Density Functional Theory (DFT-B3LYP/6-311++G(d,p)) and Hartree-Fock (HF/6-311++G(d,p)) methods. The NMR data were calculated by means of the GIAO, CSGT, and IGAIM methods. In addition, the molecular frontier orbital energies, thermodynamic parameters (in the range of 200-700 K), molecular surfaces, Mulliken charges and atomic polar tensor-based charges were investigated.

Second and third-order nonlinear optical properties and molecular parameters of azo chromophores: semiempirical analysis.

The static and frequency dependent average polarizability (<α>), first- and second-hyperpolarizabilities (<β> and <γ>) and highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO) energies of nonlinear optical chromophores with nitro acceptors 1-5 have been investigated by using the Austin Model 1 (AM1), Modified Neglect of Diatomic Overlap (MNDO), MNDO with d orbitals (MNDO-d), Parameterization Method 3 (PM3), Recife Model 1 (RM1) and Parameterization Method 6 (PM6) methods within a time-dependent Hartree-Fock (TDHF) approaches. The electronic properties of chromophores 1-5 have been reported by employing two-state model calculated at Zerner's spectroscopic version of the Intermediate Neglect of Differential Overlap singly excited configuration interaction (ZINDO/S-SCI) method. Also, the molecular hardness (η) and electronegativity (χ) parameters have been obtained by using molecular frontier orbital energies.

The consistency analysis of different semiempirical calculations on second- and third-order nonlinear optical properties of donor-acceptor chromophores containing alpha-cyan.

The static and frequency dependent average polarizability (), first- and second-hyperpolarizabilities ( and ) and HOMO and LUMO energies of donor-acceptor chromophores containing alpha-cyan (1a-c) have been investigated by using the AM1, MNDO, MNDO-d, PM3, RM1 and PM6 methods within a time-dependent Hartree-Fock (TDHF) approaches. The electronic properties of 1a-c have been reported by employing two-state model calculated at ZINDO/S-SCI, PM3-SCI and RM1-SCI methods. Also, the molecular hardness (eta) and electronegativity (chi) parameters have been obtained by using molecular frontier orbital energies.

Molecular structure and vibrational and chemical shift assignments of 3-(2-hydroxyphenyl)-4-phenyl-1H-1,2,4-triazole-5-(4H)-thione by DFT and ab initio HF calculations.

The molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) 1H and 13C chemical shift values and several thermodynamic parameters of 3-(2-Hydroxyphenyl)-4-phenyl-1H-1,2,4-triazole-5-(4H)-thione in the ground state have been calculated by using the Hartree-Fock (HF) and density functional methods (BLYP and B3LYP) with 6-31G(d) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The molecule contains one O-H.