| 초록 |
Highly selective tetramerization of ethylene by new chromium catalysts derived from diphosphine ligand complexes will be introduced. When these pre-catalysts were activated with MAO(methylaluminoxane), unprecedented chiral recognition was observed, depending on the stereochemistry of the ancillary diphosphins. In particular, (2S,3S)-(R1)2PCH(R2)CH(R2)P(R1)2(R1=Ph,R2=CH3) exhibited much higher activity(100 kg/g Cr) as well as 1-octene selectivity( 65.4 %). Rationalization of this unique catalytic system will be presented in conjunction with theoretical results. |
