| 摘要 |
A catalyst composition suitable for the trimerization of olefinic monomers, wherein the catalyst composition comprises: a) a source of chromium, molybdenum or tungsten; b) a ligand of general formula (I); <?in-line-formulae description="In-line Formulae" end="lead"?>(R<SUP>1</SUP>)(R<SUP>2</SUP>)P-X-P(R<SUP>3</SUP>)(R<SUP>4</SUP>) (I)<?in-line-formulae description="In-line Formulae" end="tail"?> wherein: X is a bivalent organic bridging group; R<SUP>1 </SUP>and R<SUP>3 </SUP>are independently selected from, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl and substituted heterohydrocarbyl groups, with the proviso that when R<SUP>1 </SUP>and R<SUP>3 </SUP>are cycloaromatic groups they do not contain a polar substituent at any of the ortho-positions; R<SUP>2 </SUP>and R<SUP>4 </SUP>are independently selected from optionally substituted cycloaromatic groups, each R<SUP>2 </SUP>and R<SUP>4 </SUP>bearing a polar substituent on at least one of the ortho-positions; and c) a cocatalyst. The present invention further relates to a process for the trimerization of olefinic monomers, particularly the trimerization of ethylene to 1-hexene, wherein the process comprises contacting at least one olefinic monomer with the catalyst composition described hereinabove. |
