We have investigated the dynamics of the F＋C4H6 reaction using the universal crossed molecular beam method. The C4H5F＋H reaction channel was observed in this experiment. Angular resolved time-of-flight spectra have ...We have investigated the dynamics of the F＋C4H6 reaction using the universal crossed molecular beam method. The C4H5F＋H reaction channel was observed in this experiment. Angular resolved time-of-flight spectra have been measured for the C4H5F product. Prod- uct angular distributions as well as kinetic energy distributions were determined for this product channel. Experimental results show that the C4H5F product is largely backward scattered with considerable forward scattering signal, relative to the F atom beam direction. This suggests that the reaction channel mainly proceeds via a long-lived complex formation mechanism, with possible contribution from a direct SN2 type mechanism.展开更多
DFT calculations have been performed to discover the mechanism for the synthesis of dimethyl adipate(DMA)by 1,3-butadiene(BD)dicarbonylation catalyzed by a complex consisting of palladium and a bidentate diphosphine l...DFT calculations have been performed to discover the mechanism for the synthesis of dimethyl adipate(DMA)by 1,3-butadiene(BD)dicarbonylation catalyzed by a complex consisting of palladium and a bidentate diphosphine ligand.The computational results indicate that BD dicarbonylation involves two catalytic stages with the same reaction mechanism including terminal alkenyl insertion,CO migratory insertion,and methanolysis.Four different reaction routes have been explored,the pathway yielding linear DMA has the lowest alkenyl CeH insertion barrier with an overall barrier of 13.4 kcal@mol^(-1)(1 kcal@mol^(-1)=4.184 kJ@mol^(-1)).The regioselectivity of the BD dicarbonylation depends mainly on the barrier of the alkenyl insertion into the palladium-hydrogen complex site.The computations well reproduced the experimentally observed linear selectivity.展开更多
文摘We have investigated the dynamics of the F＋C4H6 reaction using the universal crossed molecular beam method. The C4H5F＋H reaction channel was observed in this experiment. Angular resolved time-of-flight spectra have been measured for the C4H5F product. Prod- uct angular distributions as well as kinetic energy distributions were determined for this product channel. Experimental results show that the C4H5F product is largely backward scattered with considerable forward scattering signal, relative to the F atom beam direction. This suggests that the reaction channel mainly proceeds via a long-lived complex formation mechanism, with possible contribution from a direct SN2 type mechanism.
文摘DFT calculations have been performed to discover the mechanism for the synthesis of dimethyl adipate(DMA)by 1,3-butadiene(BD)dicarbonylation catalyzed by a complex consisting of palladium and a bidentate diphosphine ligand.The computational results indicate that BD dicarbonylation involves two catalytic stages with the same reaction mechanism including terminal alkenyl insertion,CO migratory insertion,and methanolysis.Four different reaction routes have been explored,the pathway yielding linear DMA has the lowest alkenyl CeH insertion barrier with an overall barrier of 13.4 kcal@mol^(-1)(1 kcal@mol^(-1)=4.184 kJ@mol^(-1)).The regioselectivity of the BD dicarbonylation depends mainly on the barrier of the alkenyl insertion into the palladium-hydrogen complex site.The computations well reproduced the experimentally observed linear selectivity.
