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Conformational features of a furyl‐substituted bis(tetrahydroindenyl)zirconium dichloride system
Author(s) -
Dreier Thorsten,
Hannig Frithjof,
Erker Gerhard,
Bergander Klaus,
Fröhlich Roland
Publication year - 2002
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.524
Subject(s) - chemistry , zirconium , metallocene , moiety , crystal structure , crystallography , polymer chemistry , nuclear magnetic resonance spectroscopy , molybdenum , stereochemistry , organic chemistry , polymerization , polymer
Treatment of 2‐(5‐methyl‐2‐furyl)tetrahydroindenyllithium with ZrCl 4 gave bis[2‐(5‐methyl‐2‐furyl)tetrahydroindenyl]zirconium dichloride ( 8 ). Dynamic 1 H NMR spectroscopy revealed a Cp‐furyl rotational barrier of Δ G ≠ Arrot (148 K) = 6.8 ± 0.4 kcal mol −1 . The x‐ray crystal structure analysis of 8 showed the presence of a rac ‐like metallocene conformation in which the furyl rings are oriented coplanar with the Cp moiety of the tetrahydroindenyl ligand systems, but the two furyl rings are oriented differently: one has the oxygen atom oriented toward the open front side, whereas the other has the furyl oxygen pointing toward the narrow back side of the bent metallocene wedge. The 8 –MAO Ziegler–Natta catalyst system produces an atactic polypropylene oil. Copyright© 2002 John Wiley & Sons, Ltd.