In this paper, the desulfurization of Fangshan coal was carried out by tetrachloroethylene extraction under ultrasonic and microwave irradiation. The GC-MS analysis of the tetrachloroethylene extraction reveals that organic sulfur in coal can be removed by tetrachloroethylene extract under ultrasonic and microwave irradiation. It is found that microwave irradiation time has great effect on organic sulfur removal. With the microwave irradiation time increases, the efficiency of organic sulfur removal increases. The desulphurization yield reaches maximum, 45%, when the time is 30 minutes or more. It can be clearly seen that Fangshan coal was oxidated by peroxyacetic acid under ultrasonic and microwave irradiation. From the XPS analysis of the macerals of the coal, most of the inorganic sulfur and organic sulfur are removed, especially thioether and thioalcohol which can be completely removed. These results suggest that microwave is an effective way to remove sulfur in coal.
Methodology has been developed for laying down a thin gold-on-silver film on the inner surface of glass capillaries for the purpose of catalysing benzannulation reactions. The cycloaddition precursors are flowed through these capillaries while the metal film is being heated to high temperatures using microwave irradiation. The transformation can be optimized rapidly, tolerates a wide number of functional groups, is highly regioselective, and proceeds in good to excellent conversion.
Microwave heating has been used in desulfurization of coal. Removal of organic sulfur and organic sulfur forms alterations of Xishan (XS) coal and Yunnan (YN) coal was investigated under microwave and ultrasonic irradiation. The results showed the optimum conditions for desulfurization were 50 min and 560 W for microwave and ultrasound for both coals. The desulfurization rate was maximum 23.53% for XS coal and 76.58% for YN coal. The effect of combining microwave and ultrasonic irradiation on desulfurization was stronger than simple microwave irradiation. The content of sulphone sulfur in coal was increased from the XPS after microwave and ultrasonic co-enhanced oxidative desulfurization.
3-Carboxypyridinium chlorochromate (CPCC) in the presence of aluminium chloride is a very efficient reagent for the selective oxidation of sulfides to sulfoxide and sulfones in solution and under microwave irradiation. It is noteworthy that different functional groups including carboncarbon double bonds, ketones, oximes, aldehydes, ethers, and acetals were tolerated under these reaction conditions.Key words: sulfoxides, sulfones, oxidation, chlorochromate, Lewis acid.
The present research reports the efficient synthesis of mono- and di-(aminophenyl)porphyrins and their metalation with Zn(II) using microwave irradiation. The subsequent reaction of amino-functionalized porphyrins with siloxane moieties bearing epoxy or carboxyl functional groups provided four new porphyrin-modified siloxanes. The structure of the resulting derivatives was established by 1H-NMR and MALDI-TOF-MS. The optical properties of the porphyrin chromophores were preserved, as proven by comparing the absorption and emission spectra of the initial porphyrins to those of the porphyrin-modified siloxanes.
An efficient and eco-friendly synthetic route for Friedländer quinoline synthesis of polysubstituted quinolines is described. This green chemical method starts from various 2-aminobenzophenones and mono- or dicarbonyl synthons and uses reusable Nafion NR50 material as a solid catalyst in ethanol under microwave irradiation. The protocol has a high generality of functional groups and provides the desired quinolines in good to excellent yields. Some structures were confirmed by single-crystal X-ray diffraction analysis.
Gold film-catalysed benzannulation by Microwave-Assisted, Continuous Flow Organic Synthesis (MACOS)