Spectral features, electric properties, NBO analysis and reactivity descriptors of 2-(2-Benzothiazolylthio)-Ethanol: Combined experimental and DFT studies

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 200-500nm 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.

Experimental (FT-IR, FT-Raman, UV and NMR) and quantum chemical studies on molecular structure, spectroscopic analysis, NLO, NBO and reactivity descriptors of 3,5-Difluoroaniline

Comprehensive investigation of geometrical and electronic structure in ground as well as the first excited state of 3,5-Difluoroaniline (C6H5NF2) 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.

FT-IR, FT-Raman and UV spectroscopic investigation, electronic properties, electric moments, and NBO analysis of anethole using quantum chemical calculations

FT-IR and FT-Raman spectra of anethole (1-Methoxy-4-(1-propenyl)benzene), a flavoring agent of commercial value, have been recorded in the regions 4000-400 and 4000-100cm(-1) respectively. The structure of the title molecule has been optimized and the structural parameters have been calculated by DFT/B3LYP method with 6-311++G(d,p) basis set. The fundamental vibrational wavenumbers as well as their intensities were calculated and a good agreement between observed and scaled calculated wavenumbers has been achieved. UV-Vis spectrum of the title compound was recorded in the region 200-500nm and the electronic properties such as HOMO and LUMO energies and associated energy gap were calculated by Time dependent-density functional theory (TD-DFT) approach. Nonlinear optical (NLO) study divulges the nonlinear properties of the molecule. Stability of the title molecule arising from hyper-conjugative interactions and charge delocalization has been investigated using natural bond orbital (NBO) analysis. The theoretical results were found to be in coherence with the measured experimental data.

Quantum-chemical (DFT, MP2) and spectroscopic studies (FT-IR and UV) of monomeric and dimeric structures of 2(3H)-Benzothiazolone

Molecular geometry and vibrational wavenumbers of 2(3H)-Benzothiazolone (C7H5NSO, HBT) was investigated using density functional (DFT/B3LYP) method with 6-311+G(d,p) basis set. The vibrational wavenumbers are found to be in good agreement with experimental FT-IR spectra. Hydrogen-bonded dimer of HBT, optimized by counterpoise correction, was studied by MP2 and DFT/B3LYP at the 6-311+G(d,p) level and the effects of molecular association through NH---O hydrogen bonding were discussed. A detailed analysis of the nature of the hydrogen bonding, using topological parameters, such as electronic charge density, Laplacian, kinetic and potential energy density evaluated at bond critical points (BCP) has also been presented. The UV absorption spectra of the compound dissolved in ethanol and chloroform solutions were recorded in the range of 200-600 nm. The UV-vis spectrum of the title molecule was also calculated using TD-DFT method. The calculated energy and oscillator strength almost exactly reproduce the experimental data. Total and partial density of state (TDOS, PDOS) of the HBT in terms of HOMOs and LUMOs and molecular electrostatic potential (MEP) were calculated and analyzed. The electric dipole moment, polarizability and the first static hyper-polarizability values for HBT were calculated at the DFT/B3LYP with 6-311+G(d,p) basis set. The results also show that the HBT molecule may have nonlinear optical (NLO) comportment with non-zero values. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization was analyzed using natural bond orbital (NBO) analysis.

Haematological abnormalities induced by feeding a common artificial sweetener, saccharin, in ICR Swiss mice

Haematological studies were carried out to investigate the possible deleterious effects of an extensively used artificial sweetener, saccharin, on albino mice, after feeding it for 1 year at the rate of 0.0 (control), 0.5, 1.0 and 1.5 g/kg body weight/day. Feeding of the chemical at 1.0 and 1.5 g/kg/day revealed a marked decrease in total erythrocyte count (TEC), haemoglobin content (Hb) and packed cell volume (PCV), suggesting the occurrence of anaemia. Differential leucocyte count (DLC) showed a marked increase in the number of polymorphonuclear neutrophils. Saccharin toxicity, in terms of induction of haematological abnormalities in albino mice, is discussed.

Optic lobe neurosecretory cells in Poekilocerus pictus (Orthoptera), Periplaneta americana (Dictyoptera), Belostoma indicum (Hemiptera), Polistes hebraeus (Hymenoptera) and Sandrocottus de jeani (Coleoptera)

Neurosecretory cells in the optic lobes of 5 insects viz. Poekilocerus pictus (Orthoptera), Periplaneta americana (Dictyoptera) Belostoma indicum (Hemiptera), Polistes hebraeus (Hymenoptera) and Sandrocottus dejeani(Coleoptera) have been described. They occur in the distal optic chiasma of the optic lobes in the form of a cone-shaped concentration with two arms, a dorsal and a ventral. The number of neurosecretory cells in the optic lobes varies from species to species viz., about 150 in Poekilocerus, 115 in Periplaneta, 45 in Belostoma, 90 in Polistes and 70 in Sandrocottus. They are mostly monopolar but occasionally bipolar and stain green with PAF and red or sometimes deep purple with Heidenhain's Azan technique. The axons of the monopolar cells run into the optic lobe or the brain, while those of the bipolar cells form a sort of two way connection one end going to the eye and the other to the brain. Neurosecretory cells in all the insects described above have synchronous secretory cycles.

Effect of Insecticide (BHC) on the neurosecretory cells of ventral nerve cord of adult Poekilocercus pictus (Acrididae)

Neurosecretory cells have been observed in all the ganglia of the ventral nerve cord of Poekilocerus pictus. In the suboesophageal ganglion they could be differentiated into 2 types on the basis of their staining reaction, but neurosecretory cells of all the other ganglia stain similarly. Effect of an organic insecticide BHC was observed on the neurosecretory cells of all the locations in the ventral nerve cord. Initially the insecticide acts to trigger the secretory activity but a prolonged action leads to a complete exhaustion of the secretory material which is also accompanied with many cytomorphological alterations such as loss of turgidity and compactness of the cells and appearance of undulations and sometimes complete rupture of the cell wall.

Neurosecretion in the central nervous system of an Indian spider Oxyopes sakuntale Tikader (Araneidae: Oxyopidae)

Neurosecretory cells have been observed in the entire central nervous system of an adult Indian spider Oxyopes sakuntale Tikader. These cells are present in groups at various locations in the central nervous system. They can be divided into two types on the basis of their shape, size and cytomorphic properties. Unlike insects here the median group of pars intercerebralis has very few cells. All the neruosecretory cells have similar staining reaction and can not be differentiated into types on the basis of their staining property. Majority of the cells are circular in shape, bigger in size and dark staining. In between there are few cells which are elleptical in shape, smaller in size and light staining. They all stain green with PAF (As modified by Ewen 1962) light blue with CHP (Gomori 1941) and red with HEIDENHAINS Azan stain.