Nano-SrB2O4 powder was prepared by solid-state reaction at room temperature followed by a subsequent calcination process. The highly productive method which can be operated easily confirms to the Green-chemistry princ...Nano-SrB2O4 powder was prepared by solid-state reaction at room temperature followed by a subsequent calcination process. The highly productive method which can be operated easily confirms to the Green-chemistry principles. The XRD patters demonstrate that the component of the as-obtained sample is SrB2O4 after calcination at 600℃. Differential thermal analysis and thermogravimetriy (DTA/TG) curves suggest the process of dehydration and crystal transition from Sr[B(OH)4]2 to SrB2O4·2H2O. SEM image of SrB2O4 shows that the particles are uniform and spherical with average size of 80 nm in diameter. Furthermore, the mechanism of reaction was discussed. The chemical reaction of the process is assumed to be acid-base neutralization reaction. The water generated from the acid-base neutralization reaction and the release of crystal water from Sr(OH)2·8H2O plays an essential role in the reaction system.展开更多
A simple and clean synthesis of 3,5-dicyano-1,2-dihydropyrid-2-ones by a one-pot three-component reaction of malononitrile, aromatic aldehydes and 2-cyanoacetamide or 2-cyanothioacetamide has been achieved in an aqueo...A simple and clean synthesis of 3,5-dicyano-1,2-dihydropyrid-2-ones by a one-pot three-component reaction of malononitrile, aromatic aldehydes and 2-cyanoacetamide or 2-cyanothioacetamide has been achieved in an aqueous solution with potassium carbonate as a base under microwave irradiation without a phase transfer reagent. This protocol has the advantages of short reaction time （5-8 min） and convenient work-up.展开更多
文摘Nano-SrB2O4 powder was prepared by solid-state reaction at room temperature followed by a subsequent calcination process. The highly productive method which can be operated easily confirms to the Green-chemistry principles. The XRD patters demonstrate that the component of the as-obtained sample is SrB2O4 after calcination at 600℃. Differential thermal analysis and thermogravimetriy (DTA/TG) curves suggest the process of dehydration and crystal transition from Sr[B(OH)4]2 to SrB2O4·2H2O. SEM image of SrB2O4 shows that the particles are uniform and spherical with average size of 80 nm in diameter. Furthermore, the mechanism of reaction was discussed. The chemical reaction of the process is assumed to be acid-base neutralization reaction. The water generated from the acid-base neutralization reaction and the release of crystal water from Sr(OH)2·8H2O plays an essential role in the reaction system.
基金Project supported by the National Natural Science Foundation of China （Nos. 20372057 and 20672090）, the Natural Science Foundation of Jiangsu Province （No. BK2006033）, Six Kinds of Professional Elite Foundation of the Jiangsu Province （No. 06-A-039）.
文摘A simple and clean synthesis of 3,5-dicyano-1,2-dihydropyrid-2-ones by a one-pot three-component reaction of malononitrile, aromatic aldehydes and 2-cyanoacetamide or 2-cyanothioacetamide has been achieved in an aqueous solution with potassium carbonate as a base under microwave irradiation without a phase transfer reagent. This protocol has the advantages of short reaction time （5-8 min） and convenient work-up.
