Research Article
Abraham model L solute descriptors have been determined for 127 additional mono-alkyl alkanes and polymethyl alkanes based on published gas chromatographic retention indices for solutes eluted from a fused-silica capillary column coated with a cross-lined methyl silicone stationary phase. Standard molar enthalpies of vaporization and sublimation at 298 K are calculated for the 127 mono-alkyl alkanes and polymethyl alkanes using the reported solute descriptors and our recently published Abraham model correlations. Calculated vaporization and sublimation enthalpies derived from the Abraham model compare very favourably with values based on a popular atom-group additivity model.
Keywords: Abraham model; solute descriptors; enthalpy of vaporization; enthalpy of sublimation; Kovats retention indices
Using the density functional method (DFT) in the OPBE/TZVP//QZP approximation and the Gaussian09 program, geometric parameters and total energies of molecular structures of the Mo(II), Tc(II), Ru(II), Rh(II), Pd(II), Ag(II) and Cd(II) macrotricyclic complexes with (NSSN)- and (NNNN)-coordinations of the ligand donor centers to the complex, arising as a result of complexing between M(II) indicated above, dithiooxamide H2N–C(= S)–C(= S)–NH2 and glyoxal HC(=O)–CH (=O), were calculated. Based on the data of this calculation, it is shown that in the case of Mo(II), Tc(II), Ru(II), Rh(II) and Pd (II) complexes with (NSSN)-coordination of ligand are more stable, whereas in the case of Ag(II) and Cd(II), with (NNNN)-coordination; in addition, for the Mo(II) and Ru(II) complexes, a pseudo-tetrahedral environment of the central metal ion takes place by donor atoms, while for the complexes Tc(II), Rh(II), Pd(II), Ag(II), and Cd(II) are planar ones. The bond lengths and bond angles in the indicated coordination compounds are given and it is noted that the Ag(II) and Cd(II) complexes are almost flat, the Tc(II), Rh(II), and Pd(II) complexes are small, while the Ru(II), a fairly significant deviation from coplanarity. The five-membered metal chelate cycles formed as a result of complexing, in most of these complexes are either practically flat, or exhibit a slight (within 5°) deviation from coplanarity; the only exceptions are the Mo(II) and Ru(II) complexes.
Keywords: 4d-element ion, 2,7-dithio-3,6-diazaoctadien-3,5-dithioamide-1,8, metal chelate, DFT method
Zinc oxide (ZnO) thin films are widely used in the production of high value-added technological products such as photovoltic cells, sensors, flexible and wearable electronic materials, as they are abundant in nature, easy to process, low cost and can be produced with different methods. The Chemical Bath Deposition method is preferred in the production of metal oxide thin films by changing the parameters such as pH, temperature and concentration by immersing the various substrates into the prepared solution without the need for a vacuum environment. In this study, ZnO thin films were grown on glass substrates by chemical bath deposition method. The effects of pH on the structural, morphological and optical properties of the obtained films were investigated using X-ray diffraction (XRD) method, Field Emission Scanning Electron Microscopy (FESEM) and UV-Vis Spectrophotometry respectively. It was observed that the optimum film formation took place in the Z3 series at pH 10.
Keywords: Chemical bath deposition, ZnO, thin films, pH effect