A new C 2 symmetric chiral Schiff base compound A with relatively flexible chiral environment was synthesized from L (+) tartaric acid. Its structure was determined by NMR, IR, MS etc, and its preponderant conformatio...A new C 2 symmetric chiral Schiff base compound A with relatively flexible chiral environment was synthesized from L (+) tartaric acid. Its structure was determined by NMR, IR, MS etc, and its preponderant conformation was modeled by CS Chem 3D Program. The results showed that its structure is not in a plane and has a big chiral cavity. It was showed that the complex B has different catalytic performance in asymmetric cyclopropanation of styrene and DMHD (2,5 dimethyl 2,4 hexadiene) with diazoacetate. The catalytic mechanism was also discussed.展开更多
Experimental data were presented to show the influence of solid particles on the demulsification.It was found that some solid particles could effectively resist the demulsification and increase the emulsion stability....Experimental data were presented to show the influence of solid particles on the demulsification.It was found that some solid particles could effectively resist the demulsification and increase the emulsion stability.Results were presented on the effects of the properties of the solid particles on the type and the demulsification of emulsions formed.Water-wet particles stabilize water-external emulsions,while oil-wet particles stabilize oil-external emulsions.The demulsification rate and effectiveness decrease with the mass fractions of particles.Comparing with conwentional heating,microwave radiation could enhance the demulsification rate by an order of magnitude and increase the demulsification effectiveness.For emulsions stabilized by graphite powder,the maximum demulsification effectiveness was up to 82% in 5 min under microwave radiation.However,the maximum demulsification effectiveness was 72% with oil-bath heating at 90 ℃ for 40 min.For emulsions stabilized by barium sulfate,the demulsification efficiencies all reached 100% in a very short time under microwave radiation.The investigation was also carried out on the demulsification of the emulsions stabilized by solid particles in various stearic acid concentrations.展开更多
文摘A new C 2 symmetric chiral Schiff base compound A with relatively flexible chiral environment was synthesized from L (+) tartaric acid. Its structure was determined by NMR, IR, MS etc, and its preponderant conformation was modeled by CS Chem 3D Program. The results showed that its structure is not in a plane and has a big chiral cavity. It was showed that the complex B has different catalytic performance in asymmetric cyclopropanation of styrene and DMHD (2,5 dimethyl 2,4 hexadiene) with diazoacetate. The catalytic mechanism was also discussed.
文摘Experimental data were presented to show the influence of solid particles on the demulsification.It was found that some solid particles could effectively resist the demulsification and increase the emulsion stability.Results were presented on the effects of the properties of the solid particles on the type and the demulsification of emulsions formed.Water-wet particles stabilize water-external emulsions,while oil-wet particles stabilize oil-external emulsions.The demulsification rate and effectiveness decrease with the mass fractions of particles.Comparing with conwentional heating,microwave radiation could enhance the demulsification rate by an order of magnitude and increase the demulsification effectiveness.For emulsions stabilized by graphite powder,the maximum demulsification effectiveness was up to 82% in 5 min under microwave radiation.However,the maximum demulsification effectiveness was 72% with oil-bath heating at 90 ℃ for 40 min.For emulsions stabilized by barium sulfate,the demulsification efficiencies all reached 100% in a very short time under microwave radiation.The investigation was also carried out on the demulsification of the emulsions stabilized by solid particles in various stearic acid concentrations.
