Journal of Physical and Theoretical Chemistry
Volume:14 Issue: 3, Spring 2018

The optimized structures of studied compounds 23-28 are non planner with the two phenyl at C3 and C9 are out of the molecular plane of thiazolo[3,2-a]pyridine as indicated from a dihedral angles of 710 and 1160 respectively, using DFT-B3LYP method with 6-311G(d,p) as basis set. The natural bonding orbital (NBO) analysis of the parent molecule 23 have been analyzed in terms of the hybridization of each bond, natural charges, bonding and antibonding orbital's, and second order perturbation energy (E(2)). The calculated EHOMO and ELUMO energies of the studied compounds can be used to explain the extent of charge transfer in the molecule and to calculate the global properties; the chemical hardness (η), global softness (S), electrophilicity (ω), and electronegativity (χ). The effect of substituent's of different strengths on the geometry, energetic and nonlinear optical properties are analyzed and discussed. The NLO parameters: static dipole moment (µ), polarizability (α), anisotropy polarizability (Δα), and first order hyperpolarizability (βtot), of the studied compounds have been calculated at the same level of theory and compared with the proto type Para-Nitro-Aniline (PNA). The results of (βtot) promising electrical properties. The 3D plots of the molecular electrostatic potential (MEP) for some selected compounds were investigated and describing the electrophilic and nucleophilic sites. The biological activity of the studied compounds was tested against gram positive, gram negative and Fungi. A correlation between energetic, global properties and biological activity were investigated and discussed.

By using the density function theory (DFT) the adsorption of nitramine (NH2NO2) molecule on the surface of pristine and Ni functionalized of Gallium nitride nanotube (GaNNTs) is investigated. The adsorption energy of NH2NO2 molecule on the surface of pristine and Ni functionalized GaNNTs is in range ‒6.59 to ‒48.16 Kcal/mol and is physisorption type. The ∆E and ∆H values of the all adsorption models are in range ‒10.34 to ‒47.17 Kcal/mol and ‒13.43 to ‒47.77 Kcal/mol respectively, the negative values of ∆E and ∆H reveal that the adsorption of NH2NO2 molecule on the surface of pristine and Ni functionalized GaNNTs is exothermic. The molecular electronic potential (MEP) indicates that a low electron charge is transferred from the NH2NO2 molecule toward the nanotube ones resulting in the exterior surface of nanotube is rich of electron charge. The HOMO energy of adsorbed models on the pristine GaNNTs is lower than Ni functionalized.

In the present work, the sensitivity to the moisture (hygroscopisity) is studied for 3,4-dinitropyrazole (DNP) as a famous energetic molecule. All of the DNP-H2O complex systems (1-3) as well as individual molecules were optimized and bond lengths, bond angles, dihedral angles, charge transfer and stability via NBO analysis, corrected interaction energies with ZPE + BSSE and hydrogen bonds analysis were carried out and related data were gathered and explained with details. According to the NBO analysis, it was observed that the complex 2 was the most stable one among the others. However, on the basis of the interaction energies, complex 3 displayed more strong interactions. So, it proves the existence of the strong hydrogen bonds in complexes 2 and 3 as well as occurrence of the inconsistent manner between interaction energies and charge transfer changes. Furthermore, it shows that charge transfer is not the main and effective parameter of intermolecular interactions in complexes 1-3.

In this study, carbon was easily made from walnut wood as a low-cost and non-toxic natural adsorbent. Ziziphusspina-christi (ZSAC), an excellent adsorbent, were successfully synthesized by an in chemical vapor deposition method and used for the removal of Bismark Brown(BB) dye from aqueous solution. The as-synthesized Ziziphusspina-christi (ZSAC) were characterized by FT-IR technique. Various operational parameters such as pH, initial dye concentration and contact time in batch systems were investigated on the use of Ziziphusspina-christi (ZSAC). Equilibrium data obtained have been fitted to the Langmuir, Freundlich, Tempkin, and Dubinin–Radushkevich adsorption isotherms. Langmuir isotherm best fits the experimental results. Kinetic modeling of pseudo -first order and pseudo-second order showed that the pseudo-second order equation was the most appropriate for the description of Bismark Brown(BB) dye adsorption by (ZSAC). The maximum sorption capacity qmax in Langmuir isotherm of (BB) 35.88 mg/g showed onto (ZSAC), The overall adsorption process was exothermic and spontaneous in nature. The thermodynamic functions (ΔSº, ΔHº, ΔGº) of the studied reaction are calculated using activated complex theory and show that adsorption (BB) dye onto (ZSAC) process requires heat. The results indicated that Bismark Brown(BB) adsorption onto Ziziphusspina-christi (ZSAC)might be a physical adsorption.

Now a day study on boron nitrid nanotubes are in considerable attetion due to their unique properties in different field of science. In this letter, after final optimization, thermodynamic properties analysis, stabilities, electronic structure and nuclear magnetic resonance parameters including σ isotropic and σ anisotropic tensors and asymmetric parameters of 15N and 11B nuclei are calculated. NMR spectrum of armchair boron nitrid nanotube (4, 4) with tube length of 5 nm consisting of equal numbers of 16 atoms of boron, 16 atoms of nitrogen and 16 atoms of hydrogen atoms by use of GIAO method are computed by using Hartee-Fock and different levels of density functional theory methods including B3LYP, B1LYP, LSDA, B3PW91 and BVP86 with 6-31g(d) basis set by employing Gaussian 03 package of program. Our study has revealed that this nanosemiconductor can act as a sensor in for different application, trace and also as the base of functionalizing in drug deliveries system.

In this study, multi-walled carbon nanotubes modified by N-(3-nitro-benzylidene)-N-trimethoxysilylpropyl-ethane-1, 2-diamine (NBATSPED-MWCNTs) was prepared as a low-cost and non-toxic adsorbent. These  materials was characterized by different techniques such as SEM, XRD and FT-IR and subsequently was used for the removal of humic acids (HAs) from aqueous solution. The influence of various operational parameters such as pH, initial (HAs) concentration and contact time in batch systems was investigated on the use of NBATSPED-MWCNTs. The kinetic results demonstrated that the pseudo-second- order equation is the best model to analyze the adsorption mechanism. The isotherm analysis showed that the equilibrium data are well fitted to the Langmuir isotherm model with maximum adsorption capacities of 12.5 mg g-1 of the adsorbent for removal of HAs. The overall adsorption process was exothermic and spontaneous in nature. The thermodynamic functions (ΔSº, ΔHº, ΔGº) of the studied reaction are calculated using activated complex theory and show that adsorption(HAs) onto (NBATSPED-MWCNT) process requires heat.

New antimicrobial hydrogels were prepared via reaction of functionalized-Tragacanth Gum biopolymer by glycidyltrimethylammonium chloride (QTG) with acrylamide (AM). Characterization of the QTG hydrogels with AM (QTG-AM) was carried out by thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and 1HNMR. Swelling behaviour of the QTG hydrogels was investigated on the pH, medium, and temperature, immersion time. Loading and in-vitro drug release from the final hydrogels were studied by using quercetin as a model drug. Five type of kinetic models were applied, and the release of drug from the drug-loaded hydrogels occurred through non-Fickian diffusion mechanism. The water uptake by hydrogels decreased in 0.9% NaCl solution and increased in pH 9.2. The antimicrobial effect of the prepared hydrogels QTG-AM was investigated against Candida albicans, Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. The antimicrobial results demonstrated that the hydrogels possess good antimicrobial activity against the all tested microorganism. . . .

During recent years, the silicon organic-inorganic compounds play the key role in medicinal chemistry and pharmaceutical industry. This is because of their similar chemical properties with carbon compounds. The second reason is related to their easy transfer from the cell membranes. So, molecular simulation and study the properties of novel organosilicon compounds can be more important. From this sight of view, we designed and investigated silicon analogs of benzene ring before. Here, the various derivatives of hexasiline molecule will be discussed in the following. Our investigations are based on the density functional theory (DFT) computations. The present research work was focused on investigation of the structural and spectral properties and reactivity of hexasiline using B3LYP/cc-pVDZ level of theory. The Fukui indices (local reactivity) showed that the electrophilic attacks happen on the Si4 atoms of the molecules. On the other hand, the molecules containing electron-donating and electron-withdrawing substituents prefer do nucleophilic reactions on their Si4 and Si3 positions, respectively.