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Comprehensive investigation of geometrical and electronic structure in ground as well as the first excited state of 3,5-Difluoroaniline (C 6 H 5 NF 2 ) was carried out. The experimentally observed spectral data (FT-TR and FT-Raman) of the title compound was compared with the spectral data obtained by DFT/B3LYP method using 6-311++G(d,p) basis set. The molecular properties like dipole moment, polarizability, first static hyperpolarizability, molecular electrostatic potential surface (MEPs), and contour map were calculated to get a better insight of the properties of the title molecule. Natural bond orbital (NBO) analysis was applied to study stability of the molecule arising from charge delocalization. UV–Vis spectrum of the title compound was also recorded and the electronic properties, such as Frontier orbitals and band gap energies were measured by TD-DFT approach. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were presented. Global and local reactivity descriptors were computed to predict reactivity and reactive sites on the molecule. 1 H and 13 C NMR spectra by using gauge including atomic orbital (GIAO) method of studied compound were compared with experimental data obtained. Moreover, the thermodynamic properties were evaluated. [ABSTRACT FROM AUTHOR]

The solid state Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectra of 2-Thienylboronic acid (2TBA), were recorded in the range of 4000–400 cm −1 and 4000–100 cm −1 , respectively. DFT/B3LYP theory was used for the optimization of the ground state geometry and simulation of the infrared and Raman spectra of the title molecule. To determine lowest-energy molecular conformation of the studied molecule, the selected torsion angles were varied in steps of 10° and complete 3D molecular energy profile was calculated. Among the four possible conformers ( Trans – Trans , Cis – Cis , Trans – Cis and Cis – Trans ), the most stable conformer of 2TBA is the Trans – Cis form. The vibrational wavenumbers and their assignments were carried out theoretically using the Gaussian09 set of quantum chemistry codes and the normal modes were calculated using MOLVIB program. Experimental FT-IR and FT-Raman spectra of the title compound were compared with the spectral data obtained by DFT/B3LYP method. Dipole moment, polarizability, first static hyperpolarizability and molecular electrostatic potential surface (MEPs) map have been calculated to get a better perception of the properties of the title molecule. Natural bond orbital (NBO) analysis was performed to study the stability of the molecule arising from charge delocalization. UV–Vis spectrum of the title molecule was also recorded (500–200 nm) in methanol and electronic properties such as frontier orbitals and energy gap were calculated by TD-DFT approach. The 1 H nuclear magnetic resonance (NMR) chemical shifts of the studied molecule were recorded in DMSO -d6 and calculated by Gauge-Including Atomic Orbital (GIAO) method. [ABSTRACT FROM AUTHOR]

Quantum chemical calculations of ground state energy, geometrical structure and vibrational wavenumbers, nuclear magnetic behaviors, electronic absorption spectra along with the nonlinear optical properties of 2-(2-benzothiazolylthio)-ethanol (BTZTE) were carried out using density functional (DFT/B3LYP) method with 6-311++G(d,p) as basis set. The FT-IR and FT-Raman spectra were measured in the condensed state. The fundamental vibrational wavenumbers as well as their intensities were calculated, and a good correlation between experimental and scaled calculated wavenumbers was accomplished. The electric dipole moment, polarizability and the first hyperpolarizability values of the BTZTE were calculated at the same level of theory and basis set. The results show that the BTZTE molecule possesses nonlinear optical (NLO) behavior with non-zero values. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization was analyzed using natural bond orbital (NBO) analysis. UV spectrum of the studied molecule was recorded in the region 200–500 nm and the electronic properties were predicted by time-dependent DFT approach. The calculated transition energies are in good concurrency with the experimental data. 1 H nuclear magnetic resonance (NMR) chemical shifts of the title molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The thermodynamic properties of the studied compound at different temperatures were calculated. Global and local reactivity descriptors were computed to predict reactivity and reactive sites on the molecule. [ABSTRACT FROM AUTHOR]