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• Quantum chemical simulations using DFT and vibrational analysis were performed. • Molecular interactions with several solvents were investigated. • Molecular reactive centers discovered using FUKUI, dual descriptors, and MEP analysis. • Multiwfn analysis like ELF, LOL, and ALIE depict electron density and localization. • Docking with E. coli proteins demonstrated the inhibitor action of the compound. Density functional quantum mechanical research yield a comprehensive theoretical approach on the selected organic molecule of 9,9-dihydroxynanoic acid. The DFT approach is implemented to optimise the molecular structure. The geometrical parameters of molecule were calculated. The vibrational spectrum studies were done with FT-IR and FT-Raman and their results were investigated. VEDA software is utilised to simulate PED for the basic vibrational frequencies in order to find all the vibration modes. UV–Vis analysis is performed for the gaseous phase and on solvent phases such as water, ethanol, ethyl ethanoate, acetone, and DMSO by TD-DFT-B3LYP with 6-311++G (d,p), and band gap energies are calculated. FMO investigations reported analysing the compound energy gap, softness, hardness, and electrophilicity index in gaseous phase along with a variety solvent phase. To further understand the molecule's reactive areas, Mulliken atomic charge evaluation, Fukui functions, and dual descriptors were conceptually investigated. The electro static MEP map of the compound in distinct solvent phases is provided in order to comprehend the molecular shape, size, and reactive region. The molecule's hyperpolarizability is observed to be 201.8 a.u for gas, 146.6 a.u for acetone, 138.9 a.u for DMSO, 136.3 a.u for water, and 169.8 a.u for ethyl ethanoate, will supports the molecule is good NLO material. The donor acceptor interaction has been explored so as to explain the intramolecular hyper conjugative interaction and stability. To understand the topology Multiwfn analysis like ELF, LOL and ALIE were done. The E.coli proteins are downloaded from the PDB database and fictitiously docked with our selected ligand molecule using Auto Dock software to determine hydrogen bonding and binding energy. [ABSTRACT FROM AUTHOR]

[Display omitted] • ·NLO features of 1-butyl-3-methylimidazolium dicyanamide are investigated at the M06-2X/6311++G(d,p) level of theory. • First and second hyperpolarizabilities show tremendous wavelength dependency especially in ultraviolet region. • Strong external field causes significant geometrical alterations in the structure. • Interionic charge transfer has strong effect on the electronic excitation at high frequencies. The electronic structure, inter-ionic interactions and charge transfer, polarizability, and first-order and second-order hyperpolarizabilities of 1-butyl-3-methylimidazolium dicyanamide ionic liquid have been explored via modeling at M06-2X/6-311++G(d,p) level of theory. External field intensity dependence of electronic properties was investigated by utilization of field intensity from 0.0001 to 0.002 au applied in the direction of anion-cation. Interionic interactions have been characterized through the reduced density gradient method to reveal and distinguish hydrogen bonding and other non-covalent interactions. Extraordinary bonding interactions were observed between the anion and ring system of the cation. Electronic excitation characteristics were analyzed based on the inter-fragment charge transfer method to distinguish charge transfer contributions from local excitations. Static and dynamic nonlinear optical parameters namely the total dipole moment μ , the mean polarizability α(0,0) and α(−ω; ω), the anisotropy of polarizability Δα(0,0) and Δα(−ω; ω) the first hyperpolarizability in the direction of dipole moment β(0,0,0), β(−ω; ω,0), and β (−2ω; ω,ω), the average second hyperpolarizability γ(0;0,0,0), γ(−ω; ω,0,0) and γ(−2ω; ω,ω,0) have been calculated for specific laser wavelengths corresponding to the UV, visible, and infrared region. Thus, a novel way of mapping the field intensity and wavelength dependence of NLO properties was achieved. The hyperpolarizability calculations indicate that 1-butyl-3-methylimidazolium dicyanamide has a significant potential to be used in electro-optics Pockels effect, second-harmonic generation, and electro-optical Kerr effect applications. NLO property maps indicate that the wavelength dependence in the IR and visible region is almost ignorable when compared with that of the UV region where the first hyperpolarizabilities can increase by ten thousand and the second hyperpolarizabilities can reach up to ten billion times. [ABSTRACT FROM AUTHOR]

[Display omitted] • A QSPR model was built for 7215 enthalpies of solvation and vaporization. • Five quantum chemical descriptors were used to develop the optimal QSPR model. • Quantum chemical descriptors used have definite physical meaning. • The optimal model based on random forest algorithm is very accurate. After generation of quantum chemical descriptors calculated with the GEDIIS/GDIIS optimizer in Gaussian 09, five quantum chemical descriptors related to molecular polarizability, atomic charges, charge product between solvent and solute, were selected as the optimal descriptor subset for developing quantitative structure–property relationship (QSPR) models of 7215 enthalpies of solvation and vaporization. The random forest (RF) algorithm was used to develop the RF Model Ⅰ whose dataset division for training and testing was mainly based on the solvent types. The RF Model Ⅰ has the number (n) of enthalpies of solvation and vaporization being 3633, coefficient of determination R 2 being 0.986, root mean square (rms) error being 2.598 kJ/mol for the training set and n = 3582, R 2 = 0.933, rms = 5.501 kJ/mol for the test set. The RF Model Ⅵ based on Kennard-Stone algorithm for dataset selection possesses n = 4810, R 2 = 0.987, rms = 2.550 kJ/mol (training set), n = 2405, R 2 = 0.940, rms = 4.659 kJ/mol (test set). These statistical results are very accurate, compared with other QSPR models on enthalpies of solvation reported in the literature. Furthermore, the RF Model Ⅰ and Ⅵ based on large data sets can be used for predicting both of the solvation enthalpies and vaporization enthalpies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Stable structure of Iminodiacetic Acid Hydrochloride (IAH) has been identified. • Theoretical spectrograms were simulated and compared with the experimental FT-IR and FT-Raman. • Charge transfer characteristics were examined by HOMO–LUMO and NBO analysis. • The inhibition activities of IAH against 1ESF, 1ENF, 1F77 and 4EI7 have been discussed. • Drug likeness performed to endorses pharmaceutical activity. Iminodiacetic Acid Hydrochloride (IAH) optimum geometries and vibration spectra have been determined by density functional theory computations at B3LYP with 6-311++G(d, p) level basis functions. Finding the most stable structure of IAH is done through conformational analysis. In order to interpret IR and Raman spectra both quantitatively and qualitatively, vibrational spectra have been examined based on the potential energy distribution (PED) within each vibrational mode. By means of calculations both theoretical and experimental, UV–Visible and NMR spectral studies of IAH have been performed. Utilising NBO analysis, stabilisation resulting from inter- and intramolecular interaction has been studied. For predicting the reactivity and stability of the molecule, chemical reactivity descriptors are computed. Molecule size, shape, electrical potential distribution, and point of chemical reactivity will all be revealed by mapping the charge density isosurface well with electrostatic potential surface (ESP). ELF and LOL maps intended topological aspects of IAH have also been depicted. Additionally, the Natural atomic charge and the hyperconjugative interactions that cause its NLO activity have been predicted. The hyper polarizability values indicate that these compounds could be used in electro-optical applications. IAH is screened for its pharmacological activity. The binding location of the molecule to its target protein has been predicted via a molecular docking study. [ABSTRACT FROM AUTHOR]

In this paper, we report optical studies of two higher homologous of 5O. m (m = 14,16) series which are found to exhibit negative optical anisotropy in our studies. These compounds are calamatic interdigitated with unsymmetrical alkyl chain length. The compounds show high refractive indices in our experiment. The experimentally measured refractive indices data used to calculate the molecular polarizability, order parameter, Lorentz and internal field factors. We observed that, the molecular polarizability of both the sample increases with the increase in temperature. Vuks' and Neugebauer's models are adopted for the calculation of molecular polarizabilities. Direct extrapolation method for birefringence measurements and Vuks', Neugebaur's, modified Vuks' based on Haller's extrapolation methods were used to determine the order parameter of the LC compound. The results from our study show the same nature for both the liquid crystal compounds. [ABSTRACT FROM AUTHOR]

Non-equilibrium molecular dynamics (NMD) simulations of the N,N-dimethylacetamide (DMAC) aqueous solutions using a non-polarizable field have been performed in the frequency of 1 GHz with the intensity of the E/M field in the range of 0 to 3 x 109 V/m. The principal term in the radial distribution function reveals significant differences in the structure and reorientation dynamics of DMAC-H2O interaction, indicating a substantial field-induced effect of molecular structure on the hydrogen-bond network. The first hydration shell alters significantly with increasing E/M field strength. When the intensity of the E/M field is above 3 x 108 V/m a threshold effect is observed, and the static dielectric constants decrease with increasing E/M field strength. And the molecular polarizability gradually increases when the E/M field strength increases. The average hydrogen-bond number and hydrogen-bond lifetime decline with the E/M field strength. [ABSTRACT FROM AUTHOR]

Temperature dependent optical properties like birefringence, temperature gradients of refractive indices, molecular polarizabilities, effective geometry parameter, order parameter and cross over temperatures have been investigated for nine different liquid crystal mixtures. These mixtures are prepared by mixing two pure nematic liquid crystal compounds, namely, 4-n-pentyl phenyl 4-n′-hexyloxybenzoate (ME6O.5) and 4-cyanophenyl 4′-n-pentyl benzoate (CPPB) where, ME6O.5 is a monotropic compound and CPPB is an enantiotropic compound. The mixtures however are found to be exhibit induced smectic phases. The theoretical fitting values obtained by using Hallers' extrapolated method of birefringence values agree quite well with the experimental values. It is observed that the normalized polarizability behaves exactly as refractive indices when it is plotted against temperature. The effective geometry parameter (α eg) of the mixture having highest birefringence shows highest value of α eg at certain temperature. Finally, order parameters of the mixtures have been calculated using five different techniques and for all mixtures the order parameters shows characteristics range from 0.3–0.9. The abrupt changes in order parameter before nematic phases are due to the existence of the induced smectic phases in the liquid crystal mixtures. • The values of β is observed to be decreasing with increasing concentration of CPPB in the mixtures. • The mixture having highest birefringence shows highest value of α eg at certain temperature. • An abrupt change in order parameters are observed due to the smectic phase present in the LC. [ABSTRACT FROM AUTHOR]

Five imidazole derivatives, 1-boc-imidazole (B1), 1-(trifluoroacetyl)imidazole (B2), 1-(2-hydroxyethyl)imidazole (B3), 1-(aminopropyl)imidazole (B4) and 1-ethylimidazole (B5) were analyzed for the structural, nonlinear optical, electronic and biological properties. The functional nature of the compounds were analyzed using vibrational spectra and Raman spectra and was compared with the scaled, simulated spectra obtained using the density functional theory using appropriate functional and basis set with diffused orbitals and are found to be close agreement. Relaxed potential energy scan predicts the stable conformers. Analysis of the outermost molecular orbitals gave their energy difference, aiding in the forecasting stability and other electronic properties. Time dependent density functional theory was used to analyze the electron excitation and de-excitation dynamics of these molecules and to predict the use of these molecules as effective UV photo sensitizers. This work further discusses in detail, the natural bond orbital (NBO) studies for intra molecular stabilization factors, molecular electrostatic potential (MEP) and hyperpolarizability calculations. Further molecular docking studies were conducted for the compounds with Glucanendo-1,6-beta-glucosidase and Protein-glutamatemethylesterase to predict their utility as potential inhibitors. Unlabelled Image • Spectral analysis, LHE and DSSC properties • Reactive sites are presented. • NLO properties, MEP and NBO. • Docking gives suitable results for further analysis. [ABSTRACT FROM AUTHOR]

A study on the dielectric properties of various molar concentration levels of aqueous l -glutamine, ethanol mixtures at microwave frequency region (0.02 < ν/GHz < 20) is carried out in the temperature range of 298 K to 323 K. Dielectric parameters such as dielectric permittivity, dielectric loss of different molar concentrations of l -glutamine in water, ethanol medium are evaluated. It is noticed that the real and imaginary part of dielectric permittivity increases with increase in molar concentration levels of l -glutamine in water and ethanol medium and decreases with increase in temperature. From these parameters, average relaxation time (τ), excessive inverse relaxation time (1/τ)E, excessive dielectric permittivity (εE) are determined and their behavior is analyzed in terms of the distribution of hydrogen bond network in the liquid medium. The theoretical dipole moments of l -glutamine in both aqueous and ethanol medium are determined by using DFT-B3LYP method with different solvation models. Mean molecular polarizability (α M) of the system is calculated from the Lippincott δ function potential model and compared with the Lefevre method. The activation entropy (ΔS*), activation enthalpy (ΔH*), Helmholtz energy (ΔF E ) parameters have also been evaluated and the results are correlated. Unlabelled Image • Investigation molecular interaction behavior of l -glutamine in water and ethanol medium • Temperature dependent dielectric relaxation studies in the microwave frequency region • Evaluation of excess dielectric and thermodynamic parameters • Interpretation in terms of mean molecular polarizability • Correlation between dielectric parameters in terms of bound water and hydrogen bonding [ABSTRACT FROM AUTHOR]