The title compound bis（1,3-diisopropyl-4,5-dimethylimidazolium） hexatungstate,[C11H21N2]2[W6O19],was synthesized and characterized by single-crystal X-ray diffraction,IR and elemental analysis.It crystallizes in the...The title compound bis（1,3-diisopropyl-4,5-dimethylimidazolium） hexatungstate,[C11H21N2]2[W6O19],was synthesized and characterized by single-crystal X-ray diffraction,IR and elemental analysis.It crystallizes in the monoclinic system,space group P21/n with a=1.112 84（14）,b=1.283 84（17）,c=1.293 28（17）nm,β=96.410（2）°,V=1.836 2（4）nm^3,C22H42N4O19W6,Mr=1 769.70,Dc=3.201 g/cm3,F（000）=1 596,Z=2,μ（Mo Kα）=18.797 mm-1,the final R=0.031 3,wR=0.059 8for observed reflections（I〉2σ（I））.展开更多
The preparation of divalent chromium N-heterocyclic carbene（NHC,1,3-diisopropyl4,5-dimethylimidazole-2-ylidene） compounds is reported.The reaction of 1：1 molar ratio of NHC with CrCl2 led to an isolation of [（NHC...The preparation of divalent chromium N-heterocyclic carbene（NHC,1,3-diisopropyl4,5-dimethylimidazole-2-ylidene） compounds is reported.The reaction of 1：1 molar ratio of NHC with CrCl2 led to an isolation of [（NHC）CrCl（μ-Cl）（THF）]2（1）,while that of 2：1 ratio resulted in the formation of（NHC）2CrCl2（2）.1 can be considered as an intermediate in the formation of 2 and further converted into 2 by the addition of another equiv.of NHC.The reaction of 2 with CpNa afforded an ion pair compound [（NHC）2CrCp]＋[Cp]-（3）,indicating a strong coordination ability of NHC supplanting one of the ionic Cr-Cp bonding.In combination of methylalumoxane（MAO） as cocatalyst 1 and 2 both are active for catalyzing ethylene polymerization.展开更多
基金Supported by the Beijing Higher Education Young Elite Teacher Project(YETP1191)
文摘The title compound bis（1,3-diisopropyl-4,5-dimethylimidazolium） hexatungstate,[C11H21N2]2[W6O19],was synthesized and characterized by single-crystal X-ray diffraction,IR and elemental analysis.It crystallizes in the monoclinic system,space group P21/n with a=1.112 84（14）,b=1.283 84（17）,c=1.293 28（17）nm,β=96.410（2）°,V=1.836 2（4）nm^3,C22H42N4O19W6,Mr=1 769.70,Dc=3.201 g/cm3,F（000）=1 596,Z=2,μ（Mo Kα）=18.797 mm-1,the final R=0.031 3,wR=0.059 8for observed reflections（I〉2σ（I））.
基金supported by the National Natural Science Foundation of China (20842006)the Research Fund for New Teacher of Higher Education+1 种基金the Initiation Research Fund for Returned Overseas Researchersthe 985 Project of Chinese Education Ministry
文摘The preparation of divalent chromium N-heterocyclic carbene（NHC,1,3-diisopropyl4,5-dimethylimidazole-2-ylidene） compounds is reported.The reaction of 1：1 molar ratio of NHC with CrCl2 led to an isolation of [（NHC）CrCl（μ-Cl）（THF）]2（1）,while that of 2：1 ratio resulted in the formation of（NHC）2CrCl2（2）.1 can be considered as an intermediate in the formation of 2 and further converted into 2 by the addition of another equiv.of NHC.The reaction of 2 with CpNa afforded an ion pair compound [（NHC）2CrCp]＋[Cp]-（3）,indicating a strong coordination ability of NHC supplanting one of the ionic Cr-Cp bonding.In combination of methylalumoxane（MAO） as cocatalyst 1 and 2 both are active for catalyzing ethylene polymerization.
