A one-pot three component Biginelli condensation of different substituted aromatic and aliphatic aldehydes with ethyl acetoacetate and urea to the respective 3,4-dihydropyrimidin-2-(1H)-ones under solvent-free conditi...A one-pot three component Biginelli condensation of different substituted aromatic and aliphatic aldehydes with ethyl acetoacetate and urea to the respective 3,4-dihydropyrimidin-2-(1H)-ones under solvent-free conditions that is simple,effective,and environmentally friendly was shown.Ammonium dihydrogen phosphate(NH4H2PO4) was used as a non-toxic,inexpensive,and easily available catalyst.The facile reaction condition and simple isolation and purification procedures of this method make it a good option for the synthesis of dihydropyrimidinones.展开更多
Application of sulfuric acid immobilized on silica gel as an efficient and benign catalyst has been explored in the syn-thesis of 2,4,5-Triaryl-1H-imidazoles via condensation reaction of benzil or benzoin, aldehyde an...Application of sulfuric acid immobilized on silica gel as an efficient and benign catalyst has been explored in the syn-thesis of 2,4,5-Triaryl-1H-imidazoles via condensation reaction of benzil or benzoin, aldehyde and ammonium acetate. The key advantages of this process are high yields, cost effectiveness of catalyst, easy work-up, purification of products by non-chromatographic method and the reusability of the H2SO4.SiO2 catalyst.展开更多
The pressure dependence of structural,electronic and thermoelectric properties of half-Heusler ZrNiPb was investigated in the bulk and nanosheet structures.In order to obtain the accurate results,the full-potential(li...The pressure dependence of structural,electronic and thermoelectric properties of half-Heusler ZrNiPb was investigated in the bulk and nanosheet structures.In order to obtain the accurate results,the full-potential(linearized) augmented plane-wave(FP(L)APW)calculations were performed with the Perdew-BurkeErnzerhof generalized gradient approximation(PBE-GGA)and modified Becke-Johnson(mBJ) plus spin-orbit coupling(SOC).Obtained band gap values are in close agreement with the experimental results(<0.5 eV).The variations of the thermoelectric properties of the ZrNiPb were studied under different temperatures,carrier concentrations and the hydrostatic pressures.The results show that the hydrostatic pressure decreases the lattice constant value.The band structure calculations display that the band gap increases with pressure for the bulk state and it is 0 for the nanosheet of ZrNiPb [010].The highest value of figure of merit(ZT)=0.95 is found at 9.378 GPa at a carrier concentration of n=1 × 10^18 cm^-3 at 250 K for p-type of ZrNiPb.展开更多
基金supported by the Research Council of Hakim Sabzevari University
文摘A one-pot three component Biginelli condensation of different substituted aromatic and aliphatic aldehydes with ethyl acetoacetate and urea to the respective 3,4-dihydropyrimidin-2-(1H)-ones under solvent-free conditions that is simple,effective,and environmentally friendly was shown.Ammonium dihydrogen phosphate(NH4H2PO4) was used as a non-toxic,inexpensive,and easily available catalyst.The facile reaction condition and simple isolation and purification procedures of this method make it a good option for the synthesis of dihydropyrimidinones.
文摘Application of sulfuric acid immobilized on silica gel as an efficient and benign catalyst has been explored in the syn-thesis of 2,4,5-Triaryl-1H-imidazoles via condensation reaction of benzil or benzoin, aldehyde and ammonium acetate. The key advantages of this process are high yields, cost effectiveness of catalyst, easy work-up, purification of products by non-chromatographic method and the reusability of the H2SO4.SiO2 catalyst.
文摘The pressure dependence of structural,electronic and thermoelectric properties of half-Heusler ZrNiPb was investigated in the bulk and nanosheet structures.In order to obtain the accurate results,the full-potential(linearized) augmented plane-wave(FP(L)APW)calculations were performed with the Perdew-BurkeErnzerhof generalized gradient approximation(PBE-GGA)and modified Becke-Johnson(mBJ) plus spin-orbit coupling(SOC).Obtained band gap values are in close agreement with the experimental results(<0.5 eV).The variations of the thermoelectric properties of the ZrNiPb were studied under different temperatures,carrier concentrations and the hydrostatic pressures.The results show that the hydrostatic pressure decreases the lattice constant value.The band structure calculations display that the band gap increases with pressure for the bulk state and it is 0 for the nanosheet of ZrNiPb [010].The highest value of figure of merit(ZT)=0.95 is found at 9.378 GPa at a carrier concentration of n=1 × 10^18 cm^-3 at 250 K for p-type of ZrNiPb.
