Energetics of metal–ligand binding in copper(II) and nickel(II) complexes of two Schiff bases

Abstract

The standard molar enthalpies of formation, at 298.15 K, of crystalline copper(II) and nickel(II) complexes with 4,4′-ethylenedinitrilobis(pentan-2-one) (H₂acacen) and with 1,1′-diphenyl-3,3′-ethylenedinitrilobis(butan-1-one) (H₂bzacen), were determined from solution-reaction calorimetric measurements as, respectively, Δ_fH °_m[Cu(acacen), cr] = -385.1 ± 3.2, Δ_fH °_m[Cu(bzacen), cr] = - 203.4 ± 5.1, Δ_fH °_m[Ni(acacen), cr] = -472.6 ± 3.1 and Δ_fH °_m[Ni(bzacen), cr] = -292.2 ± 5.1 kJ mol^-1. The standard molar enthalpies of sublimation of the same metal complexes, at 298.15 K, were obtained by effusion methods as: Δ_c^g_rH ° _m[Cu(acacen) = 127.6 ± 0.7, Δ_c^g_rH ° _m[Ni(acacen)] = 129.1 ± 0.9, Δ_c^g_rH ° _m[Cu(bzacen)] = 205.6 ± 3.0 and Δ_c^g_rH ° _m[Ni(bzacen) = 201.7 ± 2.8 kJ mol^-1. The differences between the mean metal–ligand and hydrogen–ligand bond-dissociation enthalpies were derived.

References

1. H. Schiff, Liebigs. Ann. Chem. Suppl., 1864, 3, 343.
2. C. Ettling, Liebigs. Ann. Chem., 1840, 35, 241.
3. K. S. Suslick and T. J. Reinert, J. Chem. Educ., 1985, 62, 974.
4. M. M. Taqui Khan, D. Srinivas, R. I. Kureshi and N. H. Khan, Inorg. Chem., 1990, 29, 2320 and refs. therein.
5. M. Calligaris, G. Nardin and L. Randaccio, Coord. Chem. Rev., 1972, 7, 385.
6. M. Calligaris and L. Randaccio, Comprehensive Coordination Chemistry, ed. G. Wilkinson, Pergamon, London, 1987, vol. 2, ch. 20.1, p. 715.
7. J. Costamagna, J. Vargas, R. Latorre, A. Alvarado and G. Mena, Coord. Chem. Rev., 1992, 119, 67.
8. A. D. Garnovskii, A. L. Nivorozhkin and V. I. Minkin, Coord. Chem. Rev., 1993, 126, 1.
9. M. A. V. Ribeiro da Silva, M. D. M. C. Ribeiro da Silva, M. C. S. S. Rangel, G. Pilcher, M. J. Akello, A. S. Carson and E. H. Jamea, Thermochim. Acta, 1990, 160, 267.
10. M. A. V. Ribeiro da Silva, M. D. M. C. Ribeiro da Silva, M. M. C. Bernardo and L. M. N. B. F. Santos, Thermochim. Acta, 1992, 205, 99.
11. M. A. V. Ribeiro da Silva, M. D. M. C. Ribeiro da Silva, J. A. B. A. Tuna and L. M. N. B. F. Santos, Thermochim. Acta, 1992, 205, 115.
12. W. D. Hemphill and D. G. Brown, Inorg. Chem., 1977, 16, 766.
13. F. M. Ashmawy, R. M. Issa, S. A. Amer, C. A. McAuliffe and R. V. Parish, J. Chem. Soc., Dalton Trans., 1986, 421.
14. M. M. Taqui Khan, N. H. Khan, R. I. Kureshy and A. B. Boricha, Inorg. Chim. Acta, 1990, 174, 175.
15. S. R. Salman and S. Noor, Thermochim. Acta, 1990, 159, 187.
16. M. Gaber, M. M. Ayad and M. I. Ayad, Thermochim. Acta, 1991, 176, 21.
17. M. I. Ayad, A. Mashaly and M. M. Ayad, Thermochim. Acta, 1991, 184, 173.
18. P. J. McCarthy, R. J. Hovey, K. Ueno and A. E. Martell, J. Am. Chem. Soc., 1955, 77, 5820.
19. A. E. Martell, R. L. Belford and M. Calvin, J. Inorg. Nucl. Chem., 1958, 5, 170.
20. D. D. Perrin and W. L. F. Armarego, Purification of Laboratory Chemicals, Pergamon, Oxford, 3rd edn., 1988.
21. Handbook of Chemistry and Physics, eds. R. C. Weast and D. R. Lide, CRC Press, Boca Raton, FL, 70th edn., 1989.
22. M. D. M. C. Ribeiro da Silva, Doctoral Thesis, University of Porto, 1985.
23. M. A. V. Ribeiro da Silva, M. D. M. C. Ribeiro da Silva and A. R. Dias, J. Organomet. Chem., 1988, 345, 105.
24. M. V. Kilday and E. J. Prosen, J. Res. Natl. Bur. Stand., Sect. A, 1973, 77, 581, 599.
25. Atomic Weights of the Elements, IUPAC, Pure Appl. Chem., 1986, 58, 1677.
26. The NBS Tables of Chemical Thermodynamics Properties, J. Phys. Chem. Ref. Data, 1982, 11, Suppl. 2.
27. J. B. Pedley, R. D. Naylor and S. P. Kirby, Thermochemical Data of Organic Compounds, Chapman and Hall, London, 2nd edn., 1986.
28. M. A. V. Ribeiro da Silva, M. D. M. C. Ribeiro da Silva, M. J. S. Monte, J. M. Gonçalves and E. M. R. Fernandes, J. Chem. Thermodyn., 1995, 27, 613.
29. M. A. V. Ribeiro da Silva and M. J. S. Monte, Thermochim. Acta, 1990, 171, 169.
30. P. M. Burkinshaw and C. T. Mortimer, J. Chem. Soc., Dalton Trans., 1984, 75.
31. C. Z. Sauerbrey, J. Phys., 1959, 155, 206.
32. CODATA, J. Chem. Thermodyn., 1978, 10, 903.
33. M. A. V. Ribeiro da Silva, M. A. R. Matos, J. M. Gonçalves, P. M. Johnson, G. Pilcher, P. M. Burkinshaw and C. T. Mortimer, Thermochim. Acta, 1994, 247, 245.
34. G. Pilcher, Pure Appl. Chem., 1989, 61, 855.