Synthesis, structural, spectral (FTIR, FT-Raman, UV, NMR), NBO and first order hyperpolarizability analysis of N-phenylbenzenesulfonamide by density functional theory

Quantum mechanical studies of p-azoxyanisole and identification of its electro-optic activity

Liquid crystals (LCs) are used in displays, visors, navigation systems and many more. Amongst a wide range of LCs, p-azoxyanisole (PAA) is considered to be an active LC. Focusing on different properties of this molecule, in the reported study, the theoretical identification of quantum mechanical parameters and the identification of electro-optic properties are carried out. Different functional theories such as B3LYP, M06-2X and M06L are used along with three basis sets 6-31G**, 6-311G and 6-311G**. A comparative study revealed that the M06-2X method produces higher values of band gap, ionization potential, electronegativity and electronic global hardness while M06L produces lower values and B3LYP gives intermediate values. Nonlinear optical properties of liquid crystals are evaluated. The nonlinear optical properties obtained for a PAA liquid crystal are much higher than those of urea. Due to its high nonlinear optical properties, our liquid crystal can be used in the field of telecommunication and optical interconnection. The order parameter and birefringence are calculated with variable electric field. We found out that the order parameter and birefringence increase with a gradually increasing electric field, which suggests that the PAA liquid crystal can be used for developing electro-optic and tunable metamaterial devices.

Solvent effects on the electronic and optical properties of Ni(II), Zn(II), and Fe(II) complexes of a Schiff base derived from 5-bromo-2-hydroxybenzaldehyde

In this article, the electronic, optical, and charge transfer properties of a Schiff base ligand prepared using 5-bromo-2-hydroxybenzaldehyde and ethyl 6-acetyl-2-amino-4,5,6,7-tetrahydrothieno[2,3- c]pyridine-3-carboxylate (C19H19BrN2O4S) and its Fe(II) (C19H30BrN2O10SClFe), Ni(II) (C19H28BrN2O9SClNi), and Zn(II) (C19H28BrN2O9SClZn) complexes are described based on different solvents environments and supported by theoretical calculations. Theoretical calculations are carried out using density functional theory (DFT/UB3LYP/LANL2DZ). The optical densities, optical band gaps, and refractive indices of the ligand and its Fe(II), Ni(II), and Zn(II) complexes in different solvent environments are obtained. The reorganization energies are calculated to determine the charge transfer rate of the studied compounds using both experimental and theoretical data. These experimental and theoretical results show that the ligand and its metal complexes can be used for optoelectronic applications and charge transfer materials in organic light-emitting diode applications.

Growth, Hirshfeld surfaces, spectral, quantum chemical calculations, photoconductivity and chemical etching analyses of nonlinear optical p-toluidine p-toluenesulfonate single crystal

A single crystal of p-toluidine p-toluenesulfonate (PTPT) has been grown by slow evaporation solution technique (SEST) at room temperature. Single crystal X-ray analysis confirms that grown crystal belongs to the monoclinic structure with space group P2₁. Intermolecular interactions and fingerprint plots of PTPT molecules are executed by Hirshfeld surface analysis. It was found that H···H (44.2%) contacts have maximum intermolecular interactions contributions in the total Hirshfeld surface area. The characteristic absorption band occurs at below 290 nm. The functional groups were identified using FTIR and FT-Raman analyses and compared with theoretical values. The title molecule contains fourteen CH bonds and three OH bonds. The calculated HOMO and LUMO energy values are -6.125 eV and -1.157 eV, respectively. The chemical potential (μ) and electronegativity (χ) values are estimated to be -3.4938 eV and 3.4938 eV, respectively. The strongest negative hyperconjugation occurs due to the charge transfer from the occupied orbital (σ) to the unoccupied orbital (π*) which is calculated for the σ(N20-C21) → π*(N20-O18). The green and red lines in the total density of states (TDOS) spectrum indicate the occupied orbital and virtual orbital levels, respectively. Photoconductivity studies have been done for the grown crystal. It is observed that the dark current is greater than photocurrent. It shows negative photoconductivity nature of PTPT crystal. The etching analysis was executed on (001) plane of PTPT crystal. It has rectangular shape etch pits patterns.

An experimental and theoretical study on a novel donor-π-acceptor bridge type 2, 4, 5-trimethoxy-4'-chlorochalcone for optoelectronic applications: A dual approach

In this article the authors aim is to investigate and analyze the various key parameters of an organic D-π-A type novel nonlinear optical material 2, 4, 5-trimethoxy-4'-chlorochalcone (2,4,5TMCC) through experimental and quantum chemical studies. The Claisen-Schmidt condensation reaction mechanism was applied to synthesize the 2,4,5TMCC compound and its single crystal was grown by a slow evaporation solution growth (low cost) technique. The crystal structure was confirmed by powder X-ray diffraction analysis. The robust vibrational study has been done using FT-IR and FT-Raman spectra and its NLO activity was discussed. The factor group analysis was also performed. The optical absorption spectrum was recorded and the band gap was calculated to be 2.8eV. In photoluminescence spectrum, an intense emission band at ~540nm has been observed which shows that the grown crystals can be used in green organic light emitting diodes and laser applications. To achieve the stable ground state molecular geometry of 2,4,5TMCC, the computational techniques were applied at different levels of theory using 6-31G* basis set. The calculated geometrical parameters and vibrational spectra are found to be in good agreement with the experimental results. To probe the optical properties of the title compound the time dependent density functional theory was applied. The excitation wavelength was observed at ~398.63nm calculated at B3LYP/6-31G* level of theory and found close to experimental value (i.e. 396nm). The static first hyperpolarizability value is found to be 136 times higher than prototype urea molecule. Additionally, the molecular level approach was attained as HOMO-LUMO gap and electrostatic potential maps. The DSC study reveals that the titled material is stable up to 149°C. The photophysical and nonlinear optical properties suggest that the titled material could be a better choice for the fabrication of optoelectronic devices.

Molecular structure, spectroscopic (IR, Raman, Ultra Violet-Visible) and nonlinear optical investigation on DCBLPZ: A novel semiorganic NLO material

Dichlorobis(L-proline) zinc(II) (DCBLPZ) is an excellent nonlinear optical (NLO) material because of its ability to exhibit high second harmonic generation and having significant optical transparency. In this work, electro-optical properties of the titled material has been thoroughly investigated by Hartree–Fock (HF) and Density functional theory using different basis sets in C1 symmetry. The calculated geometrical parametres and vibrational frequencies were found to be in good agreement with reported experimental results. Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) studies were carried out to understand the intramolecular charge transfer within the molecule. Total dipole moment ([Formula: see text]), polarizability ([Formula: see text]), anisotropy of polarizability ([Formula: see text] and first hyperpolarizability ([Formula: see text]) values were calculated. The static first hyperpolarizability value is found to be six times higher than urea. Ultra violet-visible spectrum of DCBLPZ molecule was calculated by time-dependent density functional theory (TD-DFT) in gas phase using different functionals. The calculated value of absorption wavelength was found at 234[Formula: see text]nm using TD-B3LYP/[Formula: see text]* level of theory and was in good agreement with experimental value (230[Formula: see text]nm) than other applied methods. Our results give us flexibilty to predict about possible intramolecular charge transfer from both the chlorine atoms toward both the proline units through zinc atom in the studied metallic complex. The other important parametres such as frontier molecular orbital’s (FMO), global reactivity descriptors and molecular electrostatic potential have also been calculated and discussed.

First principal studies of spectroscopic (IR and Raman, UV-visible), molecular structure, linear and nonlinear optical properties of L-arginine p-nitrobenzoate monohydrate (LANB): A new non-centrosymmetric material

In current work, the authors have been applied the density functional theory (DFT) using B3LYP and CAM-B3LYP exchange-correlation functional with 6-31G(∗) basis set on l-arginine p-nitrobenzoate monohydrate (LANB) molecule for the first time to optimize its geometry and study the spectroscopic, electronic structure, nonlinear optical properties. Vibrational modes were found in good agreement with experimental reports. The calculated UV spectra by B3LYP/6-31G(∗) and CAM-B3LYP/6-31G(∗) level of theory shows an electronic transition at ∼268 nm (4.63 eV) and 264 nm (4.70 eV) respectively. To explain the charge interaction taking place within the molecule highest occupied molecular orbital and lowest unoccupied molecular orbital were analyzed and their calculated energy gap was found to be 4.3eV with an oscillatory strength 0.3796 at B3LYP/6-31G(∗) level of theory. The dipole moment (μtot), average and anisotropy of polarizability (αtot, Δα) and static and total first hyperpolarizability (β0, βtot) values were calculated. The value of μtot and βtot are found to be 4.124D and 1.630 × 10(-30) esu and 4.127D and 1.133 × 10(-30) esu using B3LYP/6-31G(∗) and CAM-B3LYP/6-31G(∗) functional respectively. The value of βtot is >4 and >3 times higher than prototype urea molecule calculated at both level of theory, respectively. The molecular electrostatic potential (MEP), frontier molecular orbital's (FMOs), global reactivity descriptors and thermodynamic properties are also calculated and discussed. The properties of LANB calculated at B3LYP are in good correlation with experimental than the CAM-B3LYP level of theory. The obtained results show that LANB molecule can be treated as a good candidate for nonlinear optical devices.

An investigation on the key features of a D–π–A type novel chalcone derivative for opto-electronic applications

The calculated UV-visible optical spectra at different levels of theory.