Synthesis, characterization and structure of rhodium(I) carbonyl complexes with O,P-chelating 1′-(diphenylphosphino)ferrocenecarboxylate or P-monodentate 1′-(diphenylphosphino)ferrocenecarboxylic acid

Abstract

The reaction of 1′-(diphenylphosphino)ferrocenecarboxylic acid (Hdpf ) with [{Rh(µ-X)(CO)₂}₂] (X = Cl or Br) afforded rhodium(I) complexes trans-[Rh(Hdpf-P)₂X(CO)] containing the ligand as the P-bonded phosphine. On the other hand, pentane-2,4-dionato rhodium(I) complexes reacted with Hdpf by an acid–base reaction yielding novel O,P-chelated rhodium(I) complexes and pentane-2,4-dione (Hacac). The compound [Rh(acac)(CO)₂] reacted with 2 equivalents of Hdpf to give trans-[Rh(dpf-O,P)(Hdpf-P)(CO)] which exhibits proton exchange between the two forms of the ligand. Likewise, related complexes [Rh(acac)(PR₃)(CO)], where PR₃ = PCy₃, PPh₃ or PPh₂Fc (Cy = cyclohexyl, Fc = ferrocenyl), afforded the corresponding complexes trans-[Rh(dpf-O,P)(PR₃)(CO)]. The formation of the O,P chelates is regioselective and might be considered as a rather unusual displacement of pentane-2,4-dionate by the phosphinocarboxylate dpf^– with concurrent proton exchange. All the compounds were characterized by ¹H, ¹³C, ³¹P and IR spectroscopies and by FAB mass spectrometry. The crystal structure determination of trans-[Rh(dpf-O,P)(PCy₃)(CO)] confirmed the presence of an unprecedented heteroannular O,P-chelating ferrocene ligand.

References

1. C. D. Frohning, C. W. Kohlpainter and H. Brunner, in Applied Homogeneous Catalysis with Organometallic Compounds, eds. B. Cornils and W. A. Hermann, VCH, Weinheim, 1996, vol. 1, pp. 29–60, 201–219.
2. R. D. Eagling, J. E. Bateman, N. J. Goodwin, W. Henderson, B. R. Horrocks and A. Houlton, J. Chem. Soc., Dalton Trans., 1998, 1273.
3. J. Podlaha, P. Štěpnička, I. Císařová and J. Ludvík, Organometallics, 1996, 15, 543.
4. P. Štěpnička, J. Podlaha, R. Gyepes and M. Polášek, J. Organomet. Chem., 1998, 552, 293.
5. A. Jegorov, B. Kratochvíl, V. Langer and J. Podlahová, Inorg. Chem., 1984, 23, 4288.
6. A. Jegorov, J. Podlaha, J. Podlahová and F. Tureček, J. Chem. Soc., Dalton Trans., 1990, 3259.
7. B. E. Mann, C. Masters and B. L. Shaw, J. Chem. Soc. A, 1971, 1104.
8. A. W. Verstuyft, J. H. Nelson and L. W. Carry, Inorg. Chem., 1976, 15, 732 and refs. therein.
9. L. S. Bresler, N. A. Buzina, Yu. S. Varshavky, N. V. Kiseleva and T. G. Cherkasova, J. Organomet. Chem., 1979, 171, 229.
10. A. M. Trzeciak, T. Głowiak, R. Grzybek and J. J. Ziołkowski, J. Chem. Soc., Dalton Trans., 1997, 1831 and refs. therein.
11. W. R. Cullen, T.-J. Kim, F. W. B. Einstein and T. Jones, Organometallics, 1985, 4, 346.
12. H. Wang, R. J. Barton and B. E. Robertson, Acta Crystallogr., Sect. C, 1991, 47, 504.
13. A. Fulford, N. A. Bailey, H. Adams and P. M. Maitlis, J. Organomet. Chem., 1991, 417, 139.
14. S. Civiš, J. Podlahová, J. Loub and J. Ječný, Acta Crystallogr., Sect. B, 1980, 36, 1395.
15. K. R. Dunbar and S. C. Haefner, Inorg. Chem., 1992, 31, 3676; A. L. Rheingold and S. J. Geib, Acta Crystallogr., Sect. C, 1987, 43, 784; F. Dahan and R. Choukroun, Acta Crystallogr., Sect. C, 1985, 41, 704; S. E. Boyd, L. D. Field, T. W. Hambley and M. G. Partridge, Organometallics, 1993, 12, 1720.
16. T. Yoshida, K. Tani, T. Yamagata, Y. Tatsuno and T. Saito, J. Chem. Soc., Chem. Commun., 1990, 292.
17. D. Cremer and J. A. Pople, J. Am. Chem. Soc., 1975, 97, 1354.
18. S. Serron, J. Huang and S. P. Nolan, Organometallics, 1998, 17, 534.
19. Yu. S. Varshavskii and T. G. Cherkasova, Zh. Neorg. Khim., 1967, 12, 1709.
20. J. A. McCleverty and G. Wilkinson, Inorg. Synth., ed. H. F. Holtzclaw, jun., McGraw-Hill, New York, 1966, vol. 8, pp. 211–214.
21. B. F. G. Johnson, J. Lewis, P. W. Robinson and J. R. Miller, J. Chem. Soc. A, 1969, 2693.
22. L. Vallarino, J. Chem. Soc., 1957, 2287; J. A. McCleverty and G. Wilkinson, Inorganic Syntheses, ed. H. F. Holtzlaw, McGraw-Hill, New York, 1966, vol. 8, pp. 214–217.
23. A. Altomare, M. C. Burla, M. Camalli, G. Cascarano, C. Giacovazzo, A. Guagliardi and G. Polidori, J. Appl. Crystallogr., 1994, 27, 435.
24. G. M. Sheldrick, SHELXL 97, Program for Crystal Structure ReWnement from DiVraction Data, University of Göttingen, 1997.