Gold(I)-induced chelate ring-opening of palladium(II) and platinum(II) triphos complexes

Abstract

The complexes [M(triphos)Cl]Cl [triphos = PhP(CH₂CH₂PPh₂)₂; M = Pd (1), M = Pt (2)] undergo ring-opening reactions with Au(I) to give [MAu(triphos)Cl₃] [M = Pd (3), M = Pt (4) ]. In these mixed metal complexes, triphos acts as a bidentate ligand for M and the third phosphorus atom is coordinated to Au(I) with a linear geometry. Complexes 1–4 were characterised by microanalysis, FAB mass spectrometry, IR, NMR (³¹P and ¹⁹⁵Pt) spectroscopies and conductivity measurements. Complexes 2–4 were also characterised by X-ray crystallography. [Pt(triphos)Cl]Cl, 2, is monoclinic, space group P 2₁/n, with square-planar geometry. The Pt–P_central bond distance (2.207 Å) is shorter than the other two Pt–P distances (2.312 and 2.315 Å). [PdAu(triphos)Cl₃], 3, is also monoclinic (space group P 2₁/n), with square-planar Pd(II) and linear Au(I) (P–Au–Cl 177.73°), and has a similar structure to complex 4, [PtAu(triphos)Cl₃] (monoclinic, space group I  2/a). The thiolate S of the tripeptide glutathione (GSH) and N-acetyl-L-cysteine binds to [Pt(triphos)]²⁺ giving adducts with high aqueous solubility. In the presence of Au(I), 5′-GMP displaced glutathione from [Pt(triphos)(GS)]⁺ to form two adducts. Both GSH and N-acetyl-L-cysteine readily extracted Au(I) from complex 4, [PtAu(triphos)Cl₃], to give complex 2, [Pt(triphos)Cl]Cl, and the Au(I) thiolate. Since chloride and thiolates would be strong competitors to DNA binding, proteins could be possible target sites for these complexes.

References

1. F. A. Cotton and B. Hong, Prog. Inorg. Chem., 1992, 40, 179.
2. S. J. Berners-Price and P. J. Sadler, Struct. Bonding, 1988, 70, 27.
3. C. Bolm, D. Kaufmann, S. Gesslers and K. Harms, J. Organomet. Chem., 1995, 502, 47.
4. D. L. DuBois, A. Miedaner and R. C. Haltiwanger, J. Am. Chem. Soc., 1991, 113, 8753.
5. R. E. Rülke, J. G. P. Delis, A. M. Groot, C. J. Elsevier, P. W. N. M. van Leeuwen, K. Vrieze, K. Groubitz and H. Schenk, J. Organomet. Chem., 1996, 508, 109.
6. Y. Yamamoto, T. Tanase, H. Ukaji, M. Hasegawa, T. Igoshi and K. Yoshimura, J. Organomet. Chem., 1995, 498, C23.
7. T. Tanase, H. Toda and Y. Yamamoto, Inorg. Chem., 1997, 36, 1571.
8. K. D. Tan, R. Uriarte, T. J. Mazanec and D. W. Meek, J. Am. Chem. Soc., 1979, 101, 6614.
9. J. Chatt, R. Mason and D. W. Meek, J. Am. Chem. Soc., 1975, 97, 3826.
10. B. Longato, G. Pilloni, G. Valle and B. Corain, Inorg. Chem., 1988, 27, 956.
11. (a) B. Longato, G. Pilloni, G. M. Bonera and B. Corain, J. Chem. Soc., Chem. Commun., 1986, 1478; (b) B. Longato, B. Corain, G. M. Bonera and G. Pilloni, Inorg. Chim. Acta, 1987, 137, 75.
12. (a) B. Lippert, Prog. Inorg. Chem., 1989, 37, 1; (b) B. Lippert, Gazz. Chim. Ital., 1989, 118, 153 and references therein.
13. G. Bandoli, G. Trovo, A. Dolmela and B. Longato, Inorg. Chem., 1992, 31, 45.
14. A. Habtemariam and P. J. Sadler, Chem. Commun., 1996, 1785.
15. N. Margiotta, A. Habtemariam and P. J. Sadler, Angew. Chem., Int. Ed. Engl., 1997, 36, 1185.
16. P. Sevillano, A. Habtemariam, A. Castiñeiras, M. E. García and P. J. Sadler, Polyhedron, 1998, 18, 383.
17. C. E. Housecroft, B. A. M. Shaykh and A. C. Rheingold, Acta Crystallogr., Sect. C, 1990, 46, 1549.
18. E. G. Hope, W. Levason and N. A. Powell, Inorg. Chim. Acta, 1986, 115, 187.
19. R. Colton and V. Tedesco, Inorg. Chim. Acta, 1992, 202, 95.
20. R. Colton and T. Whyte, Aust. J. Chem., 1991, 44, 525.
21. W. H. Baddley, F. Basolo, H. B. Gray, C. Nölting and A. J. Poë, Inorg. Chem., 1963, 2, 921.
22. S. J. Berners-Price and P. J. Sadler, Inorg. Chem., 1986, 25, 3822.
23. E. F. de Assis and C. A. L. Filgueiras, Transition Met. Chem., 1994, 19, 484.
24. Enraf-Nonius. CAD4-Express Software, Version 5.1, Enraf-Nonius, Delft, The Netherlands, 1995.
25. A. L. Speck, HELENA, A Program for Data Reduction of CAD4 Data, University of Ultrech, The Netherlands, 1997.
26. A. L. Spek, PLATON, A Multipurpose Crystallographic Tool, University of Ultrech, The Netherlands, 1997.
27. G. M. Sheldrick, Acta Crystallogr., Sect. A, 1983, 39, 158.
28. G. M. Sheldrick, SHELXL97, Program for the Renement of Crystal Structures, University of Göttingen, Germany, 1997.
29. International Tables for X-ray Crystallography, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1995, vol. C.
30. E. Keller, SCHAKAL 92, A Computer Program for the Graphic Representation of Molecular and Crystallographic Models, University of Freiburg, Germany, 1992.
31. L. Zsolnai, ZORTEP, A Program for the Presentation of Thermal Ellipsoids, University of Heidelberg, Germany, 1997.
32. J. Casier and A. M. Glaze, J. Appl. Crystallogr., 1986, 19, 205.
33. W. Clegg, Acta Crystallogr., Sect. A, 1981, 37, 22.
34. G. M. Sheldrick, SHELXTL V. S., Siemens Analytical X-ray instruments, Madison, Wisconsin, 1995.
35. D. J. Watkin, C. K. Prout, P. W. Betteridge and J. R. Curruthers, CRYSTALS, Issue 10, Chemical Crystallography Laboratory, University of Oxford, 1996.
36. N. Walken and D. Stuart, Acta Crystallogr., Sect. A, 1983, 39, 158.
37. R. B. King, P. N. Kapoor and R. N. Kapoor, Inorg. Chem., 1971, 10, 1841.
38. A. K. Al-Sa'ady, C. A. McAullife, R. V. Parish and J. A. Sandbank, Inorg. Synth., 1985, 23, 191.
39. A. Albinati, F. Lianza, H. Berger, P. J. Pregosin, H. Rüegger and R. W. Kunz, Inorg. Chem., 1993, 32, 478.
40. W. J. Geary, Coord. Chem. Rev., 1971, 7, 81.
41. A. Handler and P. Peringer, J. Chem. Soc., Dalton Trans., 1990, 3725.
42. G. K. Anderson, H. C. Clark and J. A. Davies, Inorg. Chem., 1983, 83, 434.
43. P. E. Garrou, Chem. Rev., 1981, 81, 229.
44. K. D. Tau, R. Uriarte, T. J. Mazanec and D. W. Meek, J. Am. Chem. Soc., 1979, 101, 6614.
45. R. G. Pearson, Inorg. Chem., 1973, 12, 713.
46. W. McFarlane and J. Cass, J. Chem. Soc., Dalton Trans., 1974, 324.
47. C. J. Smith, V. S. Reddy and V. Katti, Chem. Commun., 1996, 2557.
48. G. I. Bertinsson, Acta Crystallogr., Sect. C, 1983, 39, 563.
49. F. H. Allen, O. Kennard and R. Taylor, Acc. Chem. Res., 1983, 16, 143.
50. W. C. Hamilton, Structural Chemistry and Molecular Biology, ed. A. Rich and N. Davison, Freeman, San Francisco, 1968, p. 466.
51. C. Navarro-Ranninger, F. Zamora, I. Lopez-Solera, A. Mengl and J. R. Masaguer, J. Organomet. Chem., 1996, 506, 149.
52. A. Habtemariam, P. J. Sadler, S. Parsons, A. Castiñeiras, P. Sevillano and M. E. García, 6th International Conference on the Chemistry of the Platinum Group Metals, York, UK, 1996, abstract p. 145.
53. A. G. Orpen, L. Brammer, F. H. Allen, O. Kennard, D. G. Watson and R. Taylor, J. Chem. Soc., Dalton Trans., 1989, S69.
54. G. K. Anderson and R. Kumar, Inorg. Chem., 1984, 23, 4064.
55. A. Corazza, I. Harvey and P. J. Sadler, Eur. J. Biochem., 1996, 236, 697.
56. O. M. Ni Dhubhghaill, P. J. Sadler and E. García Fernandez, Metal-Based Drugs, 1995, 2, 19.
57. L. D. Pettit, K. F. Siddiqui, H. Kozlowski and T. Kowalik, Inorg. Chim. Acta, 1981, 55, 87.
58. C.-C. Cheng and C.-H. Pai, J. Inorg. Biochem., 1998, 71, 109.
59. K. J. Barnham, M. I. Djuran, P. S. Murdoch, J. D. Ranford and P. J. Sadler, Inorg. Chem., 1996, 35, 1065.
60. K. J. Barnham, M. I. Djuran, P. S. Murdoch, J. D. Ranford and P. J. Sadler, J. Chem. Soc., Dalton Trans., 1995, 3721.
61. K. J. Barnham, Z. Guo and P. J. Sadler, J. Chem. Soc., Dalton Trans, 1996, 2867.
62. D. H. Brown and W. E. Smith, Chem. Soc. Rev., 1980, 9, 217.
63. C. K. Johnson, ORTEP, Report ORNL-5138, Oak Ridge National Laboratory, Oak Ridge, TN, 1976.