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The replacement of five-membered N-donor heterocycles from aminotrichlorogold(III) complexes. A comparison with pyridines

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Abstract

The kinetics of the process AuCl3(nu) + Cl→ AuCl 4  + nu (nu = one of a number of five-membered N-donor heterocycles covering a wide range of basicity, namely: oxazole, 2,4,5-trimethyloxazole, thiazole, 5-methylthiazole, 4-methylthiazole, 4,5-dimethylthiazole, 2,4-dimethylthiazole, 2,4,5-trimethylthiazole, imidazole and 2-methylimidazole) have been studied in methanol at 25 °C. The reactions follow the usual two-term rate law, rate = (k 1 + k 2[Cl])[complex], observed in a square-planar substitution associative-mechanism. The second-order rate constants, k 2, indicate that the discriminating ability of Au(III) in these complexes is good and markedly influenced by the nature of the leaving group. A linear-free-energy relationship, logk 2 = 0.53pK a  + constant, is observed between the rate constant and the basicity of the leaving group for its replacement by chloride. The results are compared with data from the literature regarding a series of complexes of the type AuCl3(py) (py = one of a number of pyridines) reacting with the Cl anion under the same experimental conditions. The reactivity depends not only upon ligand basicity but also upon the nature of the ligand in the order: pyridines> five-membered heterocycles. Steric factor due to the presence of a single methyl group ortho to the sp2 nitrogen atom in the ring has no influence on the rate of substitution while, surprisingly, when there are two ortho methyl groups a remarkable steric retardation effect is observable. The results are discussed in terms of reaction-profile in the associative-substitution reaction and bonding interactions in the ground and transition states.

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References

  1. M.L. Tobe, in: G. Wilkinson, R.D. Gillard, and J. McCleverty (eds) Comprehensive Coordination Chemistry, Pergamon, Oxford, 1987, vol. 1, p. 282

  2. B. Pitteri, G. Marangoni and L. Cattalini, J. Chem. Soc., Dalton Trans., 3539 (1994)

  3. B. Pitteri G. Marangoni L. Cattalini (1995) Polyhedron 14 2331 Occurrence Handle1:CAS:528:DyaK2MXotVWisbg%3D Occurrence Handle10.1016/0277-5387(95)00087-9

    Article  CAS  Google Scholar 

  4. B. Pitteri G. Marangoni F. Visentin L. Cattalini T. Bobbo (1997) Polyhedron 17 475 Occurrence Handle10.1016/S0277-5387(97)00357-4

    Article  Google Scholar 

  5. M. Bellicini, L. Cattalini, G. Marangoni and B. Pitteri, J. Chem. Soc., Dalton Trans., 1805 (1994)

  6. B. Pitteri G. Marangoni L. Cattalini F. Visentin V. Bertolasi P. Gilli (2001) Polyhedron 20 69 Occurrence Handle10.1016/S0277-5387(01)00732-X

    Article  Google Scholar 

  7. M. Bonivento L. Cattalini G. Marangoni B. Pitteri T. Bobbo (1997) Transition Met. Chem. 22 46 Occurrence Handle1:CAS:528:DyaK2sXhtl2ntbk%3D Occurrence Handle10.1023/A:1018469819983

    Article  CAS  Google Scholar 

  8. L. Cattalini M. Nicolini A. Orio (1966) Inorg. Chem. 5 1674 Occurrence Handle1:CAS:528:DyaF28XkvVGqt70%3D Occurrence Handle10.1021/ic50044a008

    Article  CAS  Google Scholar 

  9. L. Cattalini A. Orio A. Doni (1967) Inorg. Chem. 6 280 Occurrence Handle1:CAS:528:DyaF2sXltFOrtQ%3D%3D Occurrence Handle10.1021/ic50048a019

    Article  CAS  Google Scholar 

  10. L. Cattalini M.L. Tobe (1966) Inorg. Chem. 5 1145 Occurrence Handle1:CAS:528:DyaF28Xkt1Kqu7k%3D Occurrence Handle10.1021/ic50041a015

    Article  CAS  Google Scholar 

  11. F. Basolo R.G. Pearson (1967) Mechanism of Inorganic Reactions EditionNumber2 Wiley New York

    Google Scholar 

  12. D.D. Perrin (1965) Dissociation Constants of Organic Bases in Aqueous Solution Butterworths London

    Google Scholar 

  13. E. Buncel and O. Clement, J. Chem. Soc. Perkin Trans., 1333 (1995)

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Pitteri, B., Bortoluzzi, M. The replacement of five-membered N-donor heterocycles from aminotrichlorogold(III) complexes. A comparison with pyridines. Transition Met Chem 31, 1028–1033 (2006). https://doi.org/10.1007/s11243-006-0102-5

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  • DOI: https://doi.org/10.1007/s11243-006-0102-5

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