| 摘要 |
<p>Cyclic organosilicon compounds that may be employed as an electron donor for polymerization catalyst systems, polymerization catalyst systems employing the cyclic organosilicon compounds as an electron donor, methods of making the polymerization catalyst systems, and polymerization processes to produce polyolefin are disclosed. The organosilicon compounds, which are useful as electron donors in polymerization catalyst systems for the production of polyolefins, are represented by the formula: where Q1, Q2, Q3, and Q4 may be identical or different and are each hetero-atoms selected from the group consisting of N, O, S, Si, B, and P. R1, R2, R3, and R4 may be identical or different and are each hydrocarbon-based substituents to Q1, Q2, Q3, and Q4, respectively. The subscripts i, j, m, and n are independently 0 to 3. R5 and R6 may be identical or different and are each a bridging group with a backbone chain length between the two hetero-atoms Q1 and Q3, and Q2 and Q4, respectively, 1-8 atoms. The bridging group is selected from the group consisting of aliphatic, alicyclic, and aromatic bivalent radicals.</p> |
