EXCHANGE-REACTIONS BETWEEN DIALKYLZIRCONOCENE AND ALKYLALUMINIUM COMPOUNDS

被引:96
作者
SIEDLE, AR
NEWMARK, RA
LAMANNA, WM
SCHROEPFER, JN
机构
[1] 3M Corporate Research Laboratories, St. Paul
关键词
D O I
10.1016/S0277-5387(00)80583-5
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The dimethylmetallocenes Cp2Zr(13CH3)2, (Me5Cp)2Zr(13CH3)2, (indenyl)2 Zr(13CH3)2, Me2Si(C5H4)2Zr(13CH3)2 and Cp2Hf( 13CH3)2 undergo degenerate methyl exchange with the methyl-acceptor materials Me6Al2, (MeAlO)x and MeAl(2,6-di-t-butyl-4-methylphenoxy)2. Free energies, enthalpies and entropies of activation for these processes have been obtained in two solvents by 13C NMR. Increased steric hindrance at zirconium increases the free energy of activation. There appears not to be a correlation with electronic effects as assessed by gas phase appearance potentials for the (P-CH3)+ ions. © 1990.
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页码:301 / 308
页数:8
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