Synthesis, Characterization And Catalytic Property Of Dithiocarbamate Complexes And Heteropoly Acid

Five kinds of dithiocabamate ligands were prepared by a stoichiometricquantity of CS2, R2NH, NaOH, and characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy; dithiocabamate complexes were synthesized by the solid phase reaction at room temperature, and characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermal analysis, including X-ray powder diffraction to characterize solid phase reaction. Five of their single crystals were obtained and their structures were determined by X-ray diffraction. By comparison, it was found that dithiocabamate complexes often formed an exactly planar MS4 unit, such as [Mo(R2dtc)2]; and also formed a special MS 5 unit, such as [Cu2(R2dtc)4], the copper atom lies in a distorted square-pyramidal environment.Four kinds of heteropoly acids were prepared and characterized; a series of solid superacid catalyst of supported heteropoly acid were prepared and characterized; regioselectivites of chlorobenzene mononitration with nitric acid with different heteropoly acid on different supports and reaction conditions have been investigated. Experiments showed that H4SiW122O40 was the most effective in the four heteropoly acids, SiO2 nano-powders was the best supports, and the amount of acetic anhydride was the major factor. The optimum reaction conditions were: at present of acetic anhydride, a stoichiometric quantity of nitric acid, at room temperature for 40 minutes. Nitration of chlorobenzene gave a,50% yield of mononitro compounds, and an ortho-para isomer ratio 0.20 in product distribution of chlorobenzene mononitration. The process represented an attractive method for green synthesis of nitroaromatic compounds.