α-diketones and β-diketones react with Grignard reagents in the presence of a catalytic amount of Cp2TiCl2 to yield a-ketols and corresponding ketones respectively. Sulfoxides can be deoxygenated by Cp2TiCl2/Al syst...α-diketones and β-diketones react with Grignard reagents in the presence of a catalytic amount of Cp2TiCl2 to yield a-ketols and corresponding ketones respectively. Sulfoxides can be deoxygenated by Cp2TiCl2/Al system. The possible mechanisms are also discussed.展开更多
Reaction of Cp2TiCl2-Mg synthetic equivalent of practical Ti(II) reagent with propargyl alcohol derivatives affords allenyl titanium compounds in good yields.thus, providing an efficient and practical methods for synt...Reaction of Cp2TiCl2-Mg synthetic equivalent of practical Ti(II) reagent with propargyl alcohol derivatives affords allenyl titanium compounds in good yields.thus, providing an efficient and practical methods for synthesis of both allenyl and homopropargyl alcohols by the successive treatment with aldehydes and ketones.展开更多
Initiated by CP_2TiCl_2/Fe redox system,2-halotetrafluoroethyl iodides readily reacted with alkynes or alkenes to give 1:1 adducts in good to excellent yields.
Aluminum-matrix boron carbide (B4Cp/Al) is a kind of neutron absorbing material widely used in nuclear spent fuel storage. In order to improve the tensile property of B4Cp/Al composites, a new type of nano-Al2O3 parti...Aluminum-matrix boron carbide (B4Cp/Al) is a kind of neutron absorbing material widely used in nuclear spent fuel storage. In order to improve the tensile property of B4Cp/Al composites, a new type of nano-Al2O3 particle (Al2O3np) reinforced B4Cp/Al + Al2O3np composites were prepared by powder metallurgy method. The Monte Carlo particle transport program (MCNP) was used to determine the influence of Al2O3np on the thermal neutron absorptivity of composites. The universal material testing machine and scanning electron microscope (SEM) were used to study the mechanical properties, microstructure and fracture morphology of B4Cp/Al composites. The results indicated that the neutron absorption properties of B4Cp/Al composites were not affected by the addition of nano-Al2O3 particles in the range of 1 wt%-15 wt%. The addition of Al2O3np can obviously reduce the grain size of B4Cp/Al matrix metals thus improve the tensile strength of the composites. The addition threshold of Al2O3np is about 2.5 wt%. Both B4Cp and Al2O3np change the fracture characteristics of the composites from toughness to brittleness, and the latter is more important.展开更多
The oligomerization of isoprene catalyzed by Cp2TiCl2 and cocatalyst (cocatalyst = iPrMgCl, NaH, MAO(methylaluminoxane), DIBAL(diisobutylaluminum hydride))has been studied. The two dimers, 2,6dimethyl1, ...The oligomerization of isoprene catalyzed by Cp2TiCl2 and cocatalyst (cocatalyst = iPrMgCl, NaH, MAO(methylaluminoxane), DIBAL(diisobutylaluminum hydride))has been studied. The two dimers, 2,6dimethyl1, trans3,6octatriene and 3,6dimethyl1,3,6octatriene were obtained by distilling under reduced pressure and characterised by GCMS? 1HNMR? 13CNMR and GCIR. The higher oligomer which was extracted by petroleum ether was analyzed by MS and 1HNMR. The mass spectrum shows that the molar weight of the higher oligomer is within 1224, accordingly, the degree of polymerization is ranged from 3 to 18.展开更多
基金Project (No. 20072033) supported by the National Natural Science Foundation of China and the Specialized Research Fund for the Doctoral Program of Higher Education Ministry, China
文摘α-diketones and β-diketones react with Grignard reagents in the presence of a catalytic amount of Cp2TiCl2 to yield a-ketols and corresponding ketones respectively. Sulfoxides can be deoxygenated by Cp2TiCl2/Al system. The possible mechanisms are also discussed.
文摘Reaction of Cp2TiCl2-Mg synthetic equivalent of practical Ti(II) reagent with propargyl alcohol derivatives affords allenyl titanium compounds in good yields.thus, providing an efficient and practical methods for synthesis of both allenyl and homopropargyl alcohols by the successive treatment with aldehydes and ketones.
文摘Initiated by CP_2TiCl_2/Fe redox system,2-halotetrafluoroethyl iodides readily reacted with alkynes or alkenes to give 1:1 adducts in good to excellent yields.
基金Funded by Natural National Science Foundation of China(NSFC)(No.11305149)National High-Tech R&D Program(863 Program)(No.2013AA030704)。
文摘Aluminum-matrix boron carbide (B4Cp/Al) is a kind of neutron absorbing material widely used in nuclear spent fuel storage. In order to improve the tensile property of B4Cp/Al composites, a new type of nano-Al2O3 particle (Al2O3np) reinforced B4Cp/Al + Al2O3np composites were prepared by powder metallurgy method. The Monte Carlo particle transport program (MCNP) was used to determine the influence of Al2O3np on the thermal neutron absorptivity of composites. The universal material testing machine and scanning electron microscope (SEM) were used to study the mechanical properties, microstructure and fracture morphology of B4Cp/Al composites. The results indicated that the neutron absorption properties of B4Cp/Al composites were not affected by the addition of nano-Al2O3 particles in the range of 1 wt%-15 wt%. The addition of Al2O3np can obviously reduce the grain size of B4Cp/Al matrix metals thus improve the tensile strength of the composites. The addition threshold of Al2O3np is about 2.5 wt%. Both B4Cp and Al2O3np change the fracture characteristics of the composites from toughness to brittleness, and the latter is more important.
文摘The oligomerization of isoprene catalyzed by Cp2TiCl2 and cocatalyst (cocatalyst = iPrMgCl, NaH, MAO(methylaluminoxane), DIBAL(diisobutylaluminum hydride))has been studied. The two dimers, 2,6dimethyl1, trans3,6octatriene and 3,6dimethyl1,3,6octatriene were obtained by distilling under reduced pressure and characterised by GCMS? 1HNMR? 13CNMR and GCIR. The higher oligomer which was extracted by petroleum ether was analyzed by MS and 1HNMR. The mass spectrum shows that the molar weight of the higher oligomer is within 1224, accordingly, the degree of polymerization is ranged from 3 to 18.
