Selective Ethylene Tri-/Tetramerization by in situ-formed chromium catalysts stabilized by N,P-based ancillary ligand systems
Selective Ethylene Tri-/Tetramerization by in situ-formed chromium catalysts stabilized by N,P-based ancillary ligand systems
复制标题
DOI：
10.1021/cs4004968
复制
发表时间：
2013-09
期刊：
影响因子：
12.9
通讯作者：
Y. Yang;Zhen Liu;B. Liu;R. Duchateau
中科院分区：
文献类型：
--
作者：
Y. Yang;Zhen Liu;B. Liu;R. Duchateau
A series of N,P-based ancillary ligands have been synthesized, and the corresponding catalysts, formed in situ by mixing one of the N,P-ligands, Cr(acac)3 and MAO, have been tested for ethylene oligomerization. Under standard ethylene oligomerization conditions (30 bar ethylene, 60 °C, methylcyclohexane solvent), all of the in situ-formed complexes show catalytic activity, producing oligomers together with varying amounts of polyethylene (PE). Of all these combinations, only the catalyst formed by mixing N-pyrrolyldiphenylphosphine with Cr(acac)3 and MAO is capable of selectively oligomerizing ethylene, producing a mixture of 1-hexene and 1-octene in varying ratios alongside a small amount of PE. Further investigations on this catalyst system revealed that the presence of a low concentration of toluene favors the production of 1-octene. However, in pure toluene as the solvent, the selectivity toward 1-hexene/1-octene is lost and a statistic mixture of α-olefins is produced. Moreover, the choice of the coc...
