Advanced Materials Research Vols. 881-883

Abstract: A number of X···F (X=C, N, O and S) noncovalent weak intermolecular interaction systems of CH₃-F···XO₂ (X=C, N, O and S) has been investigated at B3LYP/6-311++G(d, p) computational level. A topological analysis of the electron density for the X···F (X=C, N, O and S) noncovalent weak bonds was performed using Baders theory of atom-in-molecules (AIM). The interaction content of the F···X in H₃CF···CO₂ complex would mainly represent more π property than others. The interaction energies data without (ΔE) and with (ΔE_cp) BSSE correction showed that the stability of the four complexes of the H₃CF···DB₂ system increases in the order of H₃CF···O₃ < H₃CF···NO₂ < H₃CF···CO₂ < H₃CF···SO₂.

Abstract: The article mainly argues with the latest progress of methodologies which is the introduction of a difluoromethylene unit into the organic compounds. It will also summarize the theoretical study of introducing gem-difluoromethylene group into the organic molecular. Firstly, it briefly reviews the function of difluoromethylation reaction; secondly, we start to study the recent development of introducing a CF₂ group in the organic synthesis. At last but not the least, we conclude the use of the new CF₂ unit in the syntheis of the molecular.

Abstract: In this paper, a diimine compound of 7,10-DimethylPyrazino[2,3-f][1,10]phenanthroline (dppl) and its corresponding phosphorescent Cu complexes were synthesized and characterized by 1H NMR successfully. Experimental data confirm that Cu Complex is high-energy-emitting one. The broad band emission upon excitation at λ = 440 nm with the emission maximum locates at λ = 566 nm was observed. This makes them potential candidates as cheap emitting materials.

Abstract: Tridodecylammonium 3,5-dinitro-1,2,4-1H-triazolate (TDADNT) was synthesized and characterized by NMR, IR, and Raman spectra, elemental analysis and TG/DTA. Its structure was further confirmed by the single crystal X-ray diffraction (Fig. 2), which shows that the compound crystallizes in the triclinic space group P-1 with a = 8.9507(19) Å, b = 12.702(2) Å, c = 19.068(4) Å, α = 72.440(5) ^o, β = 89.620(7) ^o, γ = 84.901(7) ^o, V = 2058.3(7) ų, Z = 2. The salt is thermally stable up to 270 °C with the TG/DTA measurements.

Abstract: Using Ca(NO3)2·4H2O, (NH4)2HPO4 and ammonia water as the starting raw materials and L-DOAP as template, hydroxyapatite (HAP) crystals were successfully prepared at 180 °C by changing the hydrothermal time. The HAP crystals were characterized by X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (FESEM). The XRD patterns indicate that increasing hydrothermal time is helpful to improve the purity of the product and enhance crystallinity of HAP crystal. The FTIR analysis shows that the carbonate ions enter into the HAP crystal lattice and the final products are carbonate-containing hydroxyapatite. The FESEM images illustrate that HAP crystal morphology changed to flower-like hierarchical structures and grass blanket-like hierarchical structures when increasing the hydrothermal time to 1 h and 24 h. Therefore, hydrothermal time has a great influence on the morphology of HAP and the possible formation mechanism of HAP samples has been discussed.

Abstract: The influencing factors of the stability for the potassium ferrate (K₂FeO₄), including pH, alkalinity, O₃, KI, KClO₃, KCl, NaClO₃ and Na₂SiO₃, were studied in this work. The results showed that the K₂FeO₄ stability in water is best at about pH=10. The higher the alkalinity is, the stronger of K₂FeO₄ stability would be. The O₃ had no effect to improve the K₂FeO₄ stability. The K₂FeO₄ stability would be best in water with 15mmol/L NaClO₃, 10mmol/L Na₂SiO₃ and 9mol/L alkalinity. Under this condition, the K₂FeO₄ content would be 83.28% after 24h.

Abstract: An easy, rapid sensitive and efficient method for the enrichment of phoxim in water sample based on enhancement effect of room temperature ionic liquid (1-butyl-3-methyl-imidazolium hexafluorophosphate, BmimPF₆) for hollow fiber membrane liquid phase microextraction coupled with high performance liquid chromatography (HPLC) has been exploited. The influences of the analytical conditions such as the extraction time, stirring speed, NaCl concentration, extraction temperature, the pH of the sample solution, were studied.

Abstract: The peak shapes of 4 anthracyclines have been investigated using isoeluotropic mixtures of acetonitrile, methanol and tetrahydrofuran (THF) in combination with formate buffer at pH 2.9 on a silica column. With aqueous or aqueous-rich mobile phases, no significant differences in overloading behavior have been found with various organic modifiers. With organic-rich mobile phases, peak shape and its dependence on sample size are notably different when organic modifier concentration is changed. Pure aqueous buffer produces the overloaded peak profiles of the solutes associated with a typical Langmuir isotherm, while distinct anti-Langmuirian peaks have been achieved with organic-rich eluents. The general similarity of the loading behavior for the solutes with acetonitrile, THF or isopropanol has been reflected either in aqueous-rich or organic-rich eluents, suggesting that the nature of organic modifier dont dominate the peak shape but water content in the mobile phases.

Abstract: Twenty-four kinds of coking coals which have different ranks are selected to investigate the sulfur transformation during coking process. The form sulfur in coals and cokes are determined by wet chemical method. The results show that the conversion of total sulfur during coal coking process is influenced by volatile content of coal and the content of the inertinite. The conversion of total sulfur is high for the large volatile content in coal. There is some linear correlation between the average conversion of total sulfur and the average inertinite content, this paper presents that the average conversion of total sulfur is high for the low average inertinite content. We also foud that coke sulfur depends primarily on the amount of coal sulfur, and the transformed capability of sulfide sulfur is stronger than that of the organic sulfur conversion for coal during coking process.

Abstract: The production and pyrophorisity of iron sulfur compounds in liquid phase were studied in order to get the spontaneous combustion rules of iron sulfur compounds producted by different ways. In the experiment, FeSO₄·7H₂O, FeCl₂·4H₂O, Fe (NO₃) ₃·9H₂O react with (NH₄)₂S_x and Na₂S·9H₂O respectively,then the pyrophorisity were analyzed by the exothermic oxidation process of sulfuration productions. The results show that, the pyrophorisity of sulfuration productions formed from (NH₄)₂S_x and dissolvable iron salt is obviously higher than formed from Na₂S and the same dissolvable iron salt. With the increase of dissolvable iron salt concentration, the oxidation pyrophorisity of sulfuration productions formed from (NH₄)₂S_x also increases. There is some pyrophorisity of sulfuration productions formed from Na₂S and dissolvable iron salt. But the pyrophorisity is faint relatively.