Hydrogen Bonds in Bis(1H-benzimidazole-κN3)cadmium(II) Dibenzoate: Hirshfeld Surface Analysis and AIM Perspective.

The coordination complex bis(1H-benzimidazole-κN3)cadmium(II) dibenzoate has been synthesized and characterized by single crystal diffraction analysis. Cadmium center is six coordinated and formed a distorted octahedron coordinated geometry. The Hirshfeld analysis shows that in the dnorm-surface of the compound, there are dark red spots near the hydrogen-bonds acceptor and donor atoms, while intermolecular interactions result in faint-red spots. The AIM analysis was performed, there exist a BCP in each N(C)-H∙∙∙O hydrogen bond, the bond paths also can be seen, the |V(b)|/G(b) < 1 and the H(b) > 0, the interaction is indicative of being a closed shell. The TG results are consistent with the X-ray diffraction structure.

[Characterization of atmospheric volatile organic compounds in Shenyang, China].

From April, 2008 to July, 2009, 187 atmospheric samples in four different seasons were collected from five sites in Shenyang. The 108 species of VOCs were measured by using the method of pre-concentration-GC-MS. The objectives of this study were to investigate the VOCs pollution level as well as its spatial and temporal distribution, and to identify the main source in Shenyang city. The results showed that the average total mass concentration of VOCs in Shenyang was 371.0 +/- 132.4 microg/m3. The major components were oxygen-containing compounds, halogenated hydrocarbon, alkanes, aromatics and alkenes, which accounted for 57.2%, 20%, 11.4%, 8.5%, and 3.0% of the total mass, respectively. A seasonal variation of VOCs across all the sampling sites was observed, with higher levels in spring and autumn and lower levels in winter and summer. Related with industrial emission, the diurnal variation of the total mean VOCs concentrations at downtown site showed three peaks in winter and two peaks in summer. The VOCs levels in the industrial and downtown areas were higher than those in other areas, with the lowest concentration observed at clean air site with no emission source around. From the results of correlation analysis and concentration ratios analysis, the VOCs pollutants in Shenyang were mainly contributed by automobile exhaust, coal & biofuel combustion, gasoline & solvent evaporation and industrial process.

[Experimental research of oil vapor pollution control for gas station with membrane separation technology].

Two kinds of membranes modules, vapor retained glassy membrane based on PEEK hollow fiber membrane modules and vapor permeated rubbery membrane system based on GMT plate-and-frame membrane modules, were used to control the oil vapor pollution during the course of receiving and transferring gasoline in oil station. The efficiencies of the membrane module and the membrane system of them were evaluated and compared respectively in the facilities which were developed by ourselves. It was found that both the two kinds of membranes modules had high efficiency for the separation of VOCs-air mixed gases, and the outlet vapor after treatment all can meet the national standard. When the vapor-enriched gas was returned to the oil tank to simulate the continuously cycle test, the concentration of VOCs in the outlet was also below 25 g x m(-3).