Synthesis, Characterization, and Polymerization Studies of Ethylenebis(hexamethylindenyl) Complexes of Zirconium and Hafnium
The chemistry of a series of ansa-bridged ethylene-bis(hexamethylindenyl) zirconium and hafnium complexes has been explored. Treatment of EBI*Li2·THF0.38 with MCl4· THF2 (M = Zr, Hf) gives rac-EBI*MCl2 (rac-2, rac-3) and meso-EBI*MCl2 (meso-2, meso-3) (M = Zr and Hf), respectively. The rac-and meso-...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
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2011
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| _version_ | 1797073076088733696 |
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| author | Ransom, P Ashley, A Brown, N Thompson, A O'Hare, D |
| author_facet | Ransom, P Ashley, A Brown, N Thompson, A O'Hare, D |
| author_sort | Ransom, P |
| collection | OXFORD |
| description | The chemistry of a series of ansa-bridged ethylene-bis(hexamethylindenyl) zirconium and hafnium complexes has been explored. Treatment of EBI*Li2·THF0.38 with MCl4· THF2 (M = Zr, Hf) gives rac-EBI*MCl2 (rac-2, rac-3) and meso-EBI*MCl2 (meso-2, meso-3) (M = Zr and Hf), respectively. The rac-and meso-isomers can be separated by fractional crystallization. meso-EBI*ZrMe2 (meso-4) can be prepared by alkylation of meso-2 with MeLi·LiBr. The molecular structures of rac-and meso-2 and rac-and meso-3 have been determined by single-crystal X-ray crystallography. A comprehensive structural comparison between these compounds and related ansa metallocenes has been carried out. rac-and meso-2 and rac-and meso-3 in the presence of modified methylaluminoxane (MMAO) are very active catalyst precursors for the polymerization of ethene to give high-density polyethene (HDPE) with molecular weights (Mw) in the range 100 000-220 000 and polydispersities (Mw/Mn) of ca. 2.6. The activities of both catalyst precursors rac-and meso-2 are some of the highest reported in the literature, at 61 800 and 38 200 kgPE/mol met/h/bar, respectively. © 2011 American Chemical Society. |
| first_indexed | 2024-03-06T23:16:48Z |
| format | Journal article |
| id | oxford-uuid:676999f9-ac91-42b1-85d6-ca186d47ddd6 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:16:48Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:676999f9-ac91-42b1-85d6-ca186d47ddd62022-03-26T18:38:00ZSynthesis, Characterization, and Polymerization Studies of Ethylenebis(hexamethylindenyl) Complexes of Zirconium and HafniumJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:676999f9-ac91-42b1-85d6-ca186d47ddd6EnglishSymplectic Elements at Oxford2011Ransom, PAshley, ABrown, NThompson, AO'Hare, DThe chemistry of a series of ansa-bridged ethylene-bis(hexamethylindenyl) zirconium and hafnium complexes has been explored. Treatment of EBI*Li2·THF0.38 with MCl4· THF2 (M = Zr, Hf) gives rac-EBI*MCl2 (rac-2, rac-3) and meso-EBI*MCl2 (meso-2, meso-3) (M = Zr and Hf), respectively. The rac-and meso-isomers can be separated by fractional crystallization. meso-EBI*ZrMe2 (meso-4) can be prepared by alkylation of meso-2 with MeLi·LiBr. The molecular structures of rac-and meso-2 and rac-and meso-3 have been determined by single-crystal X-ray crystallography. A comprehensive structural comparison between these compounds and related ansa metallocenes has been carried out. rac-and meso-2 and rac-and meso-3 in the presence of modified methylaluminoxane (MMAO) are very active catalyst precursors for the polymerization of ethene to give high-density polyethene (HDPE) with molecular weights (Mw) in the range 100 000-220 000 and polydispersities (Mw/Mn) of ca. 2.6. The activities of both catalyst precursors rac-and meso-2 are some of the highest reported in the literature, at 61 800 and 38 200 kgPE/mol met/h/bar, respectively. © 2011 American Chemical Society. |
| spellingShingle | Ransom, P Ashley, A Brown, N Thompson, A O'Hare, D Synthesis, Characterization, and Polymerization Studies of Ethylenebis(hexamethylindenyl) Complexes of Zirconium and Hafnium |
| title | Synthesis, Characterization, and Polymerization Studies of Ethylenebis(hexamethylindenyl) Complexes of Zirconium and Hafnium |
| title_full | Synthesis, Characterization, and Polymerization Studies of Ethylenebis(hexamethylindenyl) Complexes of Zirconium and Hafnium |
| title_fullStr | Synthesis, Characterization, and Polymerization Studies of Ethylenebis(hexamethylindenyl) Complexes of Zirconium and Hafnium |
| title_full_unstemmed | Synthesis, Characterization, and Polymerization Studies of Ethylenebis(hexamethylindenyl) Complexes of Zirconium and Hafnium |
| title_short | Synthesis, Characterization, and Polymerization Studies of Ethylenebis(hexamethylindenyl) Complexes of Zirconium and Hafnium |
| title_sort | synthesis characterization and polymerization studies of ethylenebis hexamethylindenyl complexes of zirconium and hafnium |
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