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Aminofluorenyl−Pentamethylcyclopentadienyl and Bis(aminofluorenyl) Derivatives of Group 4 Metals

Miller, Stephen A. and Bercaw, John E. (2000) Aminofluorenyl−Pentamethylcyclopentadienyl and Bis(aminofluorenyl) Derivatives of Group 4 Metals. Organometallics, 19 (26). pp. 5608-5613. ISSN 0276-7333. doi:10.1021/om000723r.

[img] PDF (Details of the structure determination for 4, including listings of final atomic coordinates, thermal parameters, and selected bond distances and angles; 1H NMR data employed to calculate the barrier to rotation around the C−N bond of 9; UV−visible ...) - Supplemental Material
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New group 4 compounds containing a 9-(dialkylamino)fluorenyl ligand have been prepared, and their properties and reactivities have been briefly investigated. Single-crystal X-ray analysis of {9-(N,N-dimethylamino)fluorenyl}_2ZrCl_2 (4) reveals strong zirconium−nitrogen dative bonds. The asymmetric unit contains two molecules with an unusual coordination of aminofluorenyl ligands, best described as comprised of a strong Zr−N dative interaction and essentially an η^1-fluorenyl coordination, supplemented by a weak additional C C dative interaction of one double bond of one of the benzo units. The barrier to rotation around the C−N bond of {9-(N,N-diisopropylamino)fluorenyl}(pentamethylcyclopentadienyl)ZrCl_2 (9) has been determined:  ΔG⧧(−25 °C) = 11.1 kcal·mol^(-1). Unlike related aminoborollide complexes, aminofluorenyl complexes resist quaternization by alkyl halides. Several aminofluorenyl complexes have been tested for propylene polymerization behavior in the presence of methylaluminoxane (MAO); atactic polypropylene is obtained with very low activities. The syntheses of 9-(dialkylamino)fluorene compounds are described, as are the syntheses of group 4 compounds via the corresponding 9-(dialkylamino)fluorenide lithium salts.

Item Type:Article
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URLURL TypeDescription Information
Miller, Stephen A.0000-0002-3181-1426
Additional Information:© 2000 American Chemical Society. Received August 18, 2000. Publication Date (Web): November 16, 2000. This work has been funded by the USDOE Office of Basic Energy Sciences (Grant No. DE-FG03-88ER13431) and by a DOD National Defense Science and Engineering Fellowship awarded to S.M. The authors thank Dr. Michael Day and Mr. Lawrence Henling for obtaining the X-ray crystal structure.
Funding AgencyGrant Number
Department of Energy (DOE)DE-FG03-88ER13431
National Defense Science and Engineering Graduate (NDSEG) FellowshipUNSPECIFIED
Issue or Number:26
Record Number:CaltechAUTHORS:20170524-154233004
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Official Citation:Aminofluorenyl−Pentamethylcyclopentadienyl and Bis(aminofluorenyl) Derivatives of Group 4 Metals Stephen A. Miller and John E. Bercaw Organometallics 2000 19 (26), 5608-5613 DOI: 10.1021/om000723r
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:77733
Deposited By: Tony Diaz
Deposited On:25 May 2017 19:05
Last Modified:15 Nov 2021 17:33

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