Chemical Physics Review

The ophthalmic solution with minimum concentration of preservative preparation in an appropriate packaging material appears to be most attractive approach for the process development and scale-up point of view. A simple high performance liquid chromatographic (HPLC) method for the simultaneous determination of ofolaxin in eye drops formulation was presented. Benzalkonium chloride in concentrations from 0.1% to 0.0001% induced dose-dependent growth arrest and conjunctival epithelial cell death, either delayed or immediately after administration The HPLC separation was undertaken on a inertsil C18 column using a mobile phase of water for injection. Compatibility study was assessed through measurement of factors affecting column peak symmetry, calculated using peak area and peak height of chromatogram. Assay decreased from 104 % to 102.89 % in three pieces to 101.27% in BFS, and 102.24 in glass container. Chromatographic analytical data indicated the stability of parenteral preparations in containers good enough till three months.

The influence of increasing Al concentration on the electrical, optical and structural properties of transparent and conducting films has been investigated. The films were deposited on glass substrates at a temperature of 480°C using a hydro-alcoholic solution consisting of and with various Al-doping levels from 0 to 0.53 being spray ratios of : in solution. The effect of changing the aluminum-to-tin spray ratio, [ ]/[ ], from 0 to 0.53 was investigated. The optical properties were studied in the UV/VIS/NIR region. The optical band gap for undoped films lay at 3.9 eV, whereas for high Al -doped films it shifts towards lower energies in the range of 3.9 – 3.61 eV. The results of x-ray diffraction have shown that the deposited films are polycrystalline without any second phases with preferential orientations along the (110), (101), (200) and (211) planes and an average grain size of 25.7 nm. It has been shown that increasing Al doping concentration lowers both the grain size and electrical conductivity of tin oxide significantly.

Acetoacetanilide derivatives with heterocycles have versatile applications including making agrochemicals, dyes, pigments, pharmaceuticals including vitamins, and stabilizers for PVC and polyester. Among those, 4'- Chloroacetoacetanilide was used in recombinant androgen receptor competitive binding assay for analysis of natural, synthetic and environmental chemicals. Hence in this work, the vibrational spectra and structure of 4'- Chloroacetoacetanilide (4CAA) was studied using DFT. The calculated Infrared and Raman spectra of the 4CAA compound were stimulated using the scaled force fields and the computed dipole derivatives for IR intensities and polarisability derivatives for Raman intensities.

The formation of graphene oxide–polyaniline was studied experimentally and theoretically. Both methods reveal that there is an existence of graphene oxide–polyaniline due to the interaction between oxygen functional groups of graphene oxide and polyaniline. The intercalation of polyaniline into layers of graphene oxide expands the space distance of layers in graphene oxide. The presence of polyaniline in composites can be proved by scanning electron microscope (SEM) and cyclic voltammograms of obtained composites. The formation of graphene oxide – polyaniline was also proved by theoretical calculation of adsorption energy when polyaniline interacts with graphene oxide

Multiligand homobinuclear complex of Cobalt (II) has been synthesized and characterized on the basis of elemental analysis, FTIR, TA and DSC. The complex has been assigned empirical formula as [Co(Phen.)₂(MEOA)Cl₄]H₂O. Presence of chloride, monoethanolamine ( MEOA), 1,10- phenanthroline (phen.) and metal-metal bond is verified by FTIR absorption peaks.  The appearance of ? (M-O), ? (M-N) and ? (M-O-H) bending mode supports the coordination of monoethanolamine via both oxygen and nitrogen, hence acting as a bidentate bridging ligand between two cobalt (II) centers. The coordination of 1, 10-phenanthroline has been proved by antisymmetric vibrations besides fundamental vibrations of coordinated 1,10-phenanthroline. Thermal kinetics of the complex has been studied by TG and DSC techniques. Thermal analysis shows the expulsion of water molecules in the first step below 150ºC, which verifies the presence of water as lattice water. The thermal analysis has been carried out in nitrogen atmosphere up to 800ºC. Thermograms obtained confirm FTIR data and hence supports the empirical formula. On the basis of thermal data, thermal decomposition mechanism has been proposed for the complex. Thermodynamic parameters like activation energy (E_a), pre-exponential factor (A) and entropy of activation (?S^#) has been calculated for each decomposition step, using Dolye’s, Coats and Redfern and Arrhenius method. The trend of these parameters is found to be same for all the methods involved. The reaction enthalpy is obtained from DSC technique. It shows both exothermic and endothermic peaks. The structure as depicted by empirical and FTIR spectroscopy is also proposed.

Ultrasonic velocity, absorption and EPR measurements are carried out with manganous sulphate (MnSO₄) & vanadyl sulphate (VOSO₄) salts in water-glycerine mixtures in the concentration range 0.1-0.6 (w/w). The results are discussed on the basis of Hall’s two state model and molecular interaction due to complex formation between water-glycerine and water-paramagnetic ions. The spin Hamiltonian parameters for MnSO₄ & VOSO₄ from EPR spectra have been evaluated.

The reaction between 5-(4-phenyl carbonyl methyl amino) 8-hydroxyquinoline(PHQ) and melic anhydride afforded heteronuclear bisligand namely 4-(4-(2-(8-hydroxyquinolin-5-ylamino)acetyl)phenylamino)-4-oxobut-2-enoic acid(CMHQ). The bisligand was designated as CMHQ and its co-ordination polymers with Cu+2, Zn+2, Co+2, Mn+2and Ni+2 metal ions were prepared. The co-ordination polymers and parent ligand were characterized by elemental analysis, IR, NMR spectral studies, thermogravimetry, number-average molecular weights ( ), diffuse reflectance spectral studies and magnetic susceptibilities. All co-ordination polymers and parent ligand were also monitored for microbicidal activity.

Gold nanoparticles were prepared by reduction of Chloroauric acid (HAuCl4) using enzymes of Glycyrrhiza Glabra root extract as a reducing agent and also used as stabilizer. UV–visible spectroscopy was used for quantification of Gold nanoparticle synthesis. The synthesized gold nanoparticles were characterized with Transmission electron microscopy (TEM), X-ray Diffraction (XRD) and Fourier transform Infrared Spectroscopy (FTIR).The results of TEM, XRD, and UV–vis absorption spectra show that the Gold nanoparticles have a narrow size distribution.

The crystal structure of the new complex [Cu(C5H7N3O)4]Cl2.5H2O has been determined by single crystal X-ray diffraction, and the compound was characterized by infrared spectroscopy and thermal analysis. The compound crystallizes in the monoclinic space group P21/c with lattice parameters a = 15.304(4), b = 13.528(3), c = 15.071(4) Å, ? = 90.120 (5)°, V = 3120.0 (13) Å3, and Z = 4. The solid state structure exhibits pronounced pseudosymmetry emulating an orthorhombic Pccn setting which is broken only by ordering of solvate water and chlorine anions in channels stretching along the c-axis of the unit cell. Structural and IR data indicate that the title compound is present as the keto tautomer 2-amino-6-methylpyrimidin-4-(1H)-one rather than in the enol form 2-amino-6-methyl-4-pyrimidinol. The Cu(II) atoms are four-coordinated in a square planar fashion by nitrogen atoms of four 2-amino-6-methylpyrimidin-4-(1H)-one ligands. The crystal structure is stabilized by O–H•••O, N–H•••O, N–H•••Cl and O–H•••Cl hydrogen bonds with pillars of the cationic complexes alternating with channels occupied by the chlorine anions and water molecules.

The mean free path, in edition, gas density ratio, molecule radius average time between collisions average velocity of molecule, and the diameter of the molecule for both Maxwell and Druyvestyn Velocities distribution law are performed by numerically solving the Boltzmann transport equation. This achieved for helium and nitrogen gases under influence the applied electric field to the gas pressure ratio ,E/P, between (3.9131x10-3-0.9767) and (1.611-16.115) (V cm-1 Torr-1) respectively at 3000 K. The obtained results are agreement with the experimental data.