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DOI: 10.1039/A701586K (Paper) Reference Section for: J. Chem. Soc., Dalton Trans., 1997, 2895-2902

C-Centred chiral metal alkyls, [MR*(Cl)(η-C5H5)2], rac- and meso-[ZrR*2(η-C5H5 )2] [R* = CH(SiMe3)C6H4 Me-o], and their one-electron reductions; reaction of Li[CH(SiMe3)2](Me2NCH2CH 2NMe2) with [MCl2(η-C5H5)2] (M = Zr or Hf[hair space])

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Michael F. Lappert, Colin L. Raston, Brian W. Skelton and Allan H. White

Abstract

The chloro(alkyl)metallocenes [MR*(Cl)(η-C5H5)2] [R* = -CH(SiMe3)C6 H4Me-o; M = Zr 1 or Hf 2] have been prepared from [MCl2(η-C5H5)2] and LiR*(tmen) (tmen = N,N,N′,N [hair space]′-tetramethylethane-1,2-diamine); further alkylation occurred only for M = Zr, affording rac-3a and meso-3b, [ZrR*2(η-C5H5)2]. In contrast, reaction of 2 equivalents of Li[CH(SiMe3)2](tmen) with [ZrCl2(η-C5H5)2] yielded an alkyl elimination product possessing µ-η1∶η5-C5H 42- ligands. Compound 1 was reversibly reduced (E1/2red = -1.72 V vs. saturated calomel electrode, SCE) whereas 2, 3a or 3b were irreversibly reduced (E[hair space]red = -2.12, -2.08, -2.00 V respectively vs. SCE). Thermolysis of 3b in toluene gave 3a (80 °C) or ‘Zr(C10H8)’ (120 °C). Photolysis of 3a or 3b at 20 °C in tetrahydrofuran (thf[hair space]) yielded a 1∶1 mixture of 3a and 3b; a d1 intermediate has been unambiguously identified as [ZrR*(η-C5H5)2]. Reduction of 1 (Na–Hg), or 3a and 3b (Na[C10H8]), in thf also gave [ZrR*(η-C5H5)2] but this slowly transformed into [ZrR*(η-C5H5)2(thf[hair space])], and 1 with Na[C10H8] and PPh3 gave [ZrR*(η-C5H5)2(PPh3)]. Reduction of 1, 3a or 3b, or photolysis of 3a or 3b, in the presence of PMe3 gave [ZrR*(η-C5H5)2(PMe3)]. Crystal structure determinations showed a slightly more crowded metal environment in 2 than in 1, consistent with the view that dialkylation in 2 is limited on steric grounds; M–σ-C 2.359(4) (1), 2.322(8) (2), metal–centroid 2.22 (1), 2.21 (2), M–Cl 2.444(1) (1), 2.418(3) (2) Å. The structure of 3a confirms the rac assignment, M–σ-C 2.374 Å, metal–centroid 2.23, 2.24 Å.

References

  1. Part 4, A. Antiñolo, M. F. Lappert, A. Singh, D. J. W. Winterborn, L. M. Engelhardt, C. L. Raston, A. H. White, A. J. Carty and N. J. Taylor, J. Chem. Soc., Dalton Trans., 1987, 1463 Search PubMed.
  2. M. F. Lappert, C. J. Pickett, P. I. Riley and P. I. W. Yarrow, J. Chem. Soc., Dalton Trans., 1981, 805 RSC; M. F. Lappert, P. I. Riley, P. I. W. Yarrow, J. L. Atwood, W. E. Hunter and M. J. Zaworotko, J. Chem. Soc., Dalton Trans., 1981, 814 RSC.
  3. P. B. Hitchcock, M. F. Lappert and C. R. C. Milne, J. Chem. Soc., Dalton Trans., 1981, 180 RSC.
  4. M. Brookhart, J. R. Tucker and G. R. Husk, J. Am. Chem. Soc., 1981, 103, 979 CrossRef CAS.
  5. R. M. Buchanan and C. G. Pierpont, Inorg. Chem., 1979, 19, 3608 CrossRef.
  6. H. Brunner, Adv. Organomet. Chem., 1980, 18, 151 CAS.
  7. E. A. Mintz, K. G. Molloy, T. J. Marks and V. W. Day, J. Am. Chem. Soc., 1982, 104, 4692 CrossRef.
  8. J. L. Atwood, G. K. Barker, J. Holton, W. E. Hunter, M. F. Lappert and R. Pearce, J. Am. Chem. Soc., 1977, 99, 6645 CrossRef CAS.
  9. W. Seidel, K. Fischer and K. Schmiedeknecht, Z. Anorg. Allg. Chem., 1972, 390, 273 CrossRef CAS.
  10. M. F. Lappert, L. M. Engelhardt, C. L. Raston and A. H. White, J. Chem. Soc., Chem. Commun., 1982, 1323 RSC.
  11. M. F. Lappert, in Frontiers of Organometallic Chemistry, eds. A. R. Bassindale and P. P. Gasper, Royal Society of Chemistry, Cambridge, 1991, pp. 231–252 Search PubMed.
  12. M. F. Lappert, L. M. Engelhardt, C. L. Raston and A. H. White, J. Chem. Soc., Chem. Commun., 1985, 521 RSC.
  13. J. Jeffery, M. F. Lappert and R. I. Riley, J. Organomet. Chem., 1979, 181, 25 CrossRef CAS.
  14. M. F. Lappert, C. L. Raston, B. W. Skelton and A. H. White, J. Chem. Soc., Chem. Commun., 1982, 14 RSC.
  15. M. F. Lappert, C. L. Raston, B. W. Skelton and A. H. White, J. Chem. Soc., Dalton Trans., 1984, 893 RSC.
  16. L. M. Engelhardt, W.-P. Leung, C. L. Raston and A. H. White, J. Chem. Soc., Chem. Commun., 1983, 386 RSC; L. M. Englehardt, W.-P. Leung, R. Papasergio, C. L. Raston, P. Twiss and A. H. White, J. Chem. Soc., Dalton Trans., 1987, 2347 RSC; C. L. Raston, B. W. Skelton, P. Twiss and A. H. White, Aust. J. Chem., 1988, 41, 1773 CAS.
  17. M. F. Lappert and C. L. Raston, J. Chem. Soc., Chem. Commun., 1981, 173 RSC.
  18. N. E. Schore and H. Hope, J. Am. Chem. Soc., 1980, 102, 4251 CrossRef CAS; N. E. Schore, S. J. Young, M. M. Olmstead and P. Hofmann, Organometallics, 1983, 2, 1769 CrossRef CAS.
  19. M. Etienne, R. Choukroun and D. Gervais, J. Chem. Soc., Dalton Trans., 1984, 915 RSC.
  20. A. Hudson, M. F. Lappert and R. Pichon, J. Chem. Soc., Chem. Commun., 1983, 374 RSC.
  21. G. M. Williams and J. Schwartz, J. Am. Chem. Soc., 1982, 104, 1122 CrossRef CAS.
  22. P. Czisch, G. Erker, H. G. Korth and R. Sustmann, Organometallics, 1984, 3, 945 CrossRef CAS.
  23. E. Samuel, Inorg. Chem., 1983, 22, 2967 CrossRef CAS.
  24. R. T. Baker, J. F. Whitney and S. S. Wreford, Organometallics, 1983, 2, 1049 CrossRef CAS.
  25. D. J. Cardin, M. F. Lappert, C. L. Raston and P. I. Riley, in Comprehensive Organometallic Chemistry, eds. G. Wilkinson, F. G. A. Stone and E. W. Abel, Pergamon, Oxford, 1982, vol. 3, ch. 23 Search PubMed; E. J. Ryan, in Comprehensive Organometallic Chemistry II, eds. E. W. Abel, F. G. A. Stone and G. Wilkinson, ed. M. F. Lappert, Elsevier, Amsterdam, 1995, vol. 4, ch. 8 Search PubMed; D. J. Cardin, M. F. Lappert and C. L. Raston, Chemistry of Organo-Zirconium and -Hafnium Compounds, Ellis Horwood, Chichester, 1986 Search PubMed.
  26. A.-M. Larsonneur, R. Choukroun and J. Jaud, Organometallics, 1993, 12, 3216 CrossRef CAS; R. Choukroun and F. Dahan, Organometallics, 1994, 13, 2097 CrossRef CAS; R. Choukroun, F. Dahan, A.-M. Larsonneur, E. Samuel, J. Petersen, P. Meunier and C. Sornay, Organometallics, 1991, 10, 374 CrossRef CAS.
  27. E. Samuel and J. Henique, J. Organomet. Chem., 1996, 512, 183 CrossRef CAS.
  28. P. B. Hitchcock, M. F. Lappert, G. A. Lawless, H. Olivier and E. J. Ryan, J. Chem. Soc., Chem. Commun., 1992, 474 RSC.
  29. I. F. Urazowski, V. I. Ponomaryev, I. E. Nifant'ev and D. A. Lemenovskii, J. Organomet. Chem., 1989, 368, 287 CrossRef.
  30. M. D. Fryzuk, M. Mylvaganam, M. J. Zaworotko and L. R. MacGillivray, Polyhedron, 1996, 15, 689 CrossRef CAS.
  31. R. D. Rogers and J. H. Teuben, J. Organomet. Chem., 1984, 359, 41 CrossRef CAS.
  32. H. Brand and J. Arnold, Angew. Chem., Int. Ed. Engl., 1994, 33, 95 CrossRef.
  33. R. D. Rogers, R. Vann Bynum and J. L. Atwood, J. Am. Chem. Soc., 1978, 100, 5238 CrossRef CAS.
  34. R. D. Rogers, R. Vann Bynum and J. L. Atwood, J. Am. Chem. Soc., 1981, 102, 692 CrossRef.
  35. W.-P. Leung and C. L. Raston, J. Organmomet. Chem., 1982, 240, C1 Search PubMed; L. M. Engelhardt, W.-P. Leung, C. L. Raston, P. Twiss and A. H. White, J. Chem. Soc., Dalton Trans., 1984, 331 RSC.
  36. P. J. Krusic and F. N. Tebbe, Inorg. Chem., 1982, 21, 2900 CrossRef CAS.
  37. P. C. Wailes, H. Weigold and A. P. Bell, J. Organomet. Chem., 1972, 34, 155 CrossRef CAS.
  38. S. D. Chappell and D. J. Cole-Hamilton, J. Chem. Soc., Dalton Trans., 1983, 1051 RSC; S. D. Chappell, D. J. Cole-Hamilton, A. M. R. Galas and M. B. Hursthouse, J. Chem. Soc., Dalton Trans., 1982, 1867 RSC.
  39. K. I. Gell, T. V. Harris and J. Schwartz, Inorg. Chem., 1981, 20, 481 CrossRef CAS.
  40. M. A. Beswick and D. S. Wright, in Comprehensive Organometallic Chemistry II, eds. E. W. Abel, F. G. A. Stone and G. Wilkinson, vol. ed. C. E. Housecroft, Elsevier, Amsterdam, 1995, vol. 1, ch. 1 and refs. therein Search PubMed.
  41. S. P. Patterman, J. L. Karle and G. D. Stucky, J. Am. Chem. Soc., 1970, 92, 1150 CrossRef CAS.
  42. L. M. Engelhardt, W.-P. Leung, C. L. Raston, P. Twiss and A. H. White, J. Chem. Soc., Dalton Trans., 1984, 321 RSC.
  43. L. M. Engelhardt, W.-P. Leung, C. L. Raston, G. Salem, P. Twiss and A. H. White, J. Chem. Soc., Dalton Trans., 1988, 2403 RSC.
  44. S. I. Bailey, D. Colgan, L. M. Engelhardt, W.-P. Leung, R. I. Papasergio, C. L. Raston and A. H. White, J. Chem. Soc., Dalton Trans., 1986, 603 RSC.
  45. N. El Murr, A. Chaloyard and J. Tirouflet, J. Chem. Soc., Chem. Commun., 1980, 446 RSC.
  46. G. S. Bristow, M. F. Lappert, T. R. Martin, J. L. Atwood and W. E. Hunter, J. Chem. Soc., Dalton Trans., 1984, 399 RSC.
  47. E. Samuel, P. Mallard and C. Giannotti, J. Organomet. Chem., 1977, 142, 289 CrossRef CAS; P. W. N. M. van Leeuwen, H. van der Heijden, C. F. Roobeek and J. H. G. Frijns, J. Organomet. Chem., 1981, 209, 169 CrossRef CAS.
  48. J. M. Atkinson, P. B. Brindley, A. G. Davies and J. A.-A. Hawari, J. Organomet. Chem., 1984, 264, 253 CrossRef CAS.
  49. H. G. Alt, Angew. Chem., Int. Ed. Engl., 1984, 23, 766 CrossRef.
  50. G. R. Davies, J. A. J. Jarvis and B. T. Kilbourn, Chem. Commun., 1971, 1511 RSC.
  51. Y. Dusausoy, J. Protas, P. Renaut, B. Gautheron and G. Tainturier, J. Organomet. Chem., 1978, 157, 167 CrossRef CAS.
  52. J. Jeffery, M. F. Lappert, N. T. Luong-Thi, J. L. Atwood and W. E. Hunter, J. Chem. Soc., Chem. Commun., 1978, 1081 RSC.
  53. C. J. Cardin, D. J. Cardin, T. J. King, R. J. Norton, H. E. Parge and A. Roy, cited in ref. 25.
  54. C. H. Saldorriaga-Molina, A. Clearfield and I. Bernal, Inorg. Chem., 1974, 13, 2880 CrossRef.
  55. J. L. Atwood, W. E. Hunter, D. C. Hrncir, E. Samuel, H. Alt and M. D. Rausch, Inorg. Chem., 1975, 14, 1757 CrossRef CAS.
  56. C. J. Pickett and D. Pletcher, J. Chem. Soc., Dalton Trans., 1975, 879 RSC.
  57. International Tables for X-Ray Crystallography;, eds. J. A. Ibers and W. C. Hamilton, Kynoch Press, Birmingham, 1974, vol. 4 Search PubMed.
  58. The X-RAY System, Version of March 1976, Technical Report TR-446, ed. J. M. Stewart, Computer Science Centre, University of Maryland, 1976.
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