Synthesis of new adducts and co-ordination complexes of zirconium and titanium containing β-aminoketone ligands. Crystal structures of isostructural adducts MCl₄·2PrⁱHNCMe[double bond, length half m-dash]CHCMe[double bond, length half m-dash]O (M = Ti or Zr) and the complex [Zr(PhNCMe[double bond, length half m-dash]CHCMe[double bond, length half m-dash]O)₂Cl₂]

Abstract

The reaction of MCl₄ (M = Zr or Ti) with β-aminoketones HL (R¹HNCR²[double bond, length half m-dash]CHCR³[double bond, length half m-dash]O; R² = R³ = Me; R² = Me, R³ = CF₃) yielded the bis(ligand) adducts MCl₄·2HL (M = Zr, R¹ = Prⁱ or Ph; R² = R³ = Me; or R¹ = Prⁱ, R² = Me, R³ = CF₃; M = Ti, R¹ = Prⁱ or CH₂CH[double bond, length half m-dash]CH₂, R² = R³ = Me). Reaction of MCl₄ with the alkali-metal salts of the β-aminoketone ligands yielded the bis(ligand) complexes [M(R¹NCMe[double bond, length half m-dash]CHCMe[double bond, length half m-dash]O)₂Cl₂] (M = Zr, R¹ = Ph, p-ClC₆H₄, p-MeOC₆H₄ or Prⁱ; M = Ti, R¹ = Ph or p-MeOC₆H₄). Crystal structure determinations of the isostructural compounds ZrCl₄·2PrⁱHNCMe[double bond, length half m-dash]CHCMe[double bond, length half m-dash]O and TiCl₄·2PrⁱHNCMe[double bond, length half m-dash]CHCMe[double bond, length half m-dash]O indicated an octahedral co-ordination environment around the metal with the trans monodentate N–O ligands bound through the oxygen only. Strong intramolecular hydrogen bonding of the hydrogen on the nitrogen with the ligand oxygen is consistent with a ligand immonium enolate structure. An X-ray study of the octahedral complex [Zr(PhNCMe[double bond, length half m-dash]CHCMe[double bond, length half m-dash]O)₂Cl₂] indicated that the oxygens of the chelating N–O ligands are trans to each other and the chloride ligands are in a cis arrangement. The plane of one N–O chelate is in the equatorial plane of the complex and the plane of the second N–O ligand is at right angles to the first. The ligand forms a predominantly delocalised chelate ring but some ene–imine structure is apparent.

References

1. R. C. Fay, in Comprehensive Coordination Chemistry, The Synthesis, Reactions, Properties and Applications of Coordination Compounds, eds. G. Wilkinson, R. D. Gillard and J. A. McCleverty, Pergamon, Exeter, 1st edn., 1987, vol. 3, pp. 32, 363–451.
2. F. Corazza, E. Solari, C. Floriani, A. Chiesi-Villa and C. Guastini, J. Chem. Soc., Dalton Trans., 1990, 1335.
3. E. B. Tjaden, D. C. Swenson, R. F. Jordan and J. L. Petersen, Organometallics, 1995, 14, 371.
4. C. Floriani, Polyhedron, 1989, 8, 1717.
5. M. Mazzanti, J. M. Rosset, C. Floriani, A. Chiesi-Villa and C. Guastini, J. Chem. Soc., Dalton Trans., 1989, 953.
6. J. M. Rosset, C. Floriani, M. Mazzanti, A. Chiesi-Villa and C. Guastini, Inorg. Chem., 1990, 29, 3991.
7. D. G. Black, D. C. Swenson, R. F. Jordan and R. D. Rogers, Organometallics, 1995, 14, 3539.
8. G. Dellamico, F. Marchetti and C. Floriani, J. Chem. Soc., Dalton Trans., 1982, 2197.
9. E. Solari, C. Floriani, A. Chiesi-Villa and C. Rizzoli, J. Chem. Soc., Dalton Trans., 1992, 367.
10. D. J. Jones, K. J. Cavell and W. Keim, unpublished work.
11. D. J. Jones, K. J. Cavell and W. Keim, Aust. Prov. Pat., PO 4397, 1996.
12. M. Peukert and W. Keim, Organometallics, 1983, 2, 594.
13. B. Reuben and H. Wittcoff, J. Chem. Educ., 1988, 65, 605.
14. A. Behr and W. Keim, Arab. J. Sci. Eng., 1985, 10, 377.
15. K. Robards, E. Patsalides and S. Dilli, J. Chromatogr., 1987, 411, 1.
16. G. W. Everett, jun. and R. H. Holm, J. Am. Chem. Soc., 1965, 87, 2117.
17. G. O. Dudek and R. H. Holm, J. Am. Chem. Soc., 1962, 84, 2961.
18. P. Veya, C. Floriani, A. Chiesi-Villa and C. Rizzoli, Organometallics, 1993, 12, 4892.
19. D. F. Martin, G. A. Janusonis and B. B. Martin, J. Am. Chem. Soc., 1961, 83, 73.
20. H. K. Shin, M. J. Hampden-Smith, T. T. Kodas and A. L. Rheingold, J. Chem. Soc., Chem. Commun., 1992, 217.
21. L. E. Manzer, Inorg. Synth., 1982, 21, 135.
22. R. Claverini, P. Ganis and C. Pedone, J. Organomet. Chem., 1973, 50, 327.
23. A. L. P.-Ù. Spek, PLATON, University of Utrecht, 1994.