Homogeneous Ethylene-Polymerization Catalysts Based on Alkyl Cations of the Rare-Earth Metals: Are Dicationic Mono(alkyl) Complexes the Active Species?

Angewandte Chemie - International Edition

Volumn 42, Issue 41, 2003, Pages 5075-5079

  Arndt, Stefan ^a   Spaniol, Thomas P ^a   Okuda, Jun ^a,b  

^a JOHANNES GUTENBERG UNIVERSITY   (Germany)

^b RWTH AACHEN UNIVERSITY   (Germany)

Author keywords

Alkyl ligands; Aluminum; Cations; Polymerization; Rare earth elements

Indexed keywords

COMPLEXATION; POLYMERIZATION; POSITIVE IONS; RARE EARTH ELEMENTS;

DICATIONS;

CATALYSIS;

ALKYL GROUP; ALUMINUM; CATION; COORDINATION COMPOUND; ETHYLENE; LANTHANIDE; LIGAND;

ARTICLE; CATALYST; COMPLEX FORMATION; CRYSTAL STRUCTURE; GEOMETRY; IONIZATION; POLYMERIZATION; REACTION ANALYSIS; X RAY ANALYSIS;

EID: 0242323505     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.200352532     Document Type: Article

References (29)

1. R. F. Jordan, Adv. Organomet. Chem. 1991, 32, 325-387.
2. a) C. J. Schaverien, Organometallics 1992, 11, 3476-3478;
3. a) S. Hajela, W. P. Schaefer, J. E. Bercaw, J. Organomet. Chem. 1997, 532, 45-53.
4. S. Bambirra, D. van Leusen, A. Meetsma, B. Hessen, J. H. Teuben, Chem. Commun. 2001, 637-638.
5. P. G. Hayes, W. E. Piers, R. McDonald, J. Am. Chem. Soc. 2002, 124, 2132-2133.
6. S. Bambirra, D. van Leusen, A. Meetsma, B. Hessen, J. H. Teuben, Chem. Commun. 2003, 522-523.
7. For the preparation by using a one-pot synthesis, see: M. F. Lappert, R. Pearce, J. Chem. Soc. Chem. Commun. 1973, 126-127.
8. + (x=1, CE=12-crown-4; x=0, CE=15-crown-5, 18-crown-6), see: S. Arndt, T. P. Spaniol, J. Okuda, Chem. Commun. 2002, 896-897.
9. R. D. Shannon, Acta Crystallogr Sect. A 1976, 32, 751-767.
10. In principle, cationic aluminum alkyls could be also considered as ethylene polymerization catalyst, see: a) J. S. Kim, L. M. Wojcinski II, S. Liu, J. C. Sworen, A. Sen, J. Am. Chem. Soc. 2000, 122, 5668-5669;
11. b) K.-C. Kim, C. A. Reed, G. S. Long, A. Sen, J. Am. Chem. Soc. 2002, 124, 7662-7663.
12. 4], no polymerization of ethylene is observed.
13. 4] as dormant species, see: M. Bochmann, S. J. Lancaster, Angew. Chem. 1994, 106, 1715-1718; Angew. Chem. Int. Ed. Engl. 1994, 33,1634-1637.
14. 4] as dormant species, see: M. Bochmann, S. J. Lancaster, Angew. Chem. 1994, 106, 1715-1718; Angew. Chem. Int. Ed. Engl. 1994, 33,1634-1637.
15. 2], see: F. Guerin, J. C. Stewart, C. Beddie, D. W. Stephan, Organometallics 2000, 19, 2994-3000;
16. 2l, see: E. Y.-X. Chen, W. J. Kruper, G. Roof, D. R. Wilson, J. Am. Chem. Soc. 2001, 123, 745-746.
17. 6 coordinated arene adduct of a monocationic scandium methyl complex was crystallographically characterized, see: P. G. Hayes, W. E. Piers, M. Parvez, J. Am. Chem. Soc. 2003, 125, 5622-5623.
18. 3.
19. 7Y: C 74.16, H 8.00; found: C 73.27, H 7.22;
20. -) contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/conts/retrieving.html (or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB21EZ, UK; fax: (+44) 1223-336-033; or deposit@ccdc.cam.ac.uk).
21. For pertinent Y-C bond lengths, see: K. C. Hultzsch, P. Voth, K. Beckerle, T. P. Spaniol, J. Okuda, Organometallics 2000, 19, 228-243.
22. -· THF: Y-O=2.405(5), 2.411(5), 2.391(5), 2.422(5), 2.408(5) Å, see: W. J. Evans, J. M. Olofson, J.W. Ziller, J. Am. Chem. Soc. 1990, 112, 2308-2314;
23. -: Y-O=2.391(7), 2.368(5), 2.382(6) Å, see: P. Sobota, J. Utko, S. Szafert, Inorg. Chem. 1994, 33, 5203-5206;
24. -: Y-O= 2.378(8), 2.377(7), 2.396(8), 2.401(7), 2.309(7) Å, see: K. Chiu, Z. Zhang, T. C. W. Mak, Z. Xie, J. Organomet. Chem. 2000, 614, 107-112;
25. -: Y-O= 2×2.354(4), 2.448(4), 2.479(4) Å, this work
26. Not surprisingly, ethylene was also polymerized when methylaluminoxane was used instead of aluminum trialkyl; see Table 2.
27. 2, see: C. Götz, A. Rau, G. Luft, J. Mol. Catal. A 2002, 184, 95-110.
28. Higher coordination numbers 7 and 8 were reported for cationic alkyl complexes of lutetium, see reference [7].
29. 3, see: S. Kaita, Z. Hou, M. Nishiura, Y. Doi, J. Kurazumi, A. C. Horiuchi, Y. Wakatsuki, Macromol. Rapid Commun. 2003, 24, 179-184.