Structural Chemistry

, Volume 4, Issue 5, pp 323–325 | Cite as

The mean enthalpy of the lanthanide-oxygen bond in 2,2,6,6-tetramethyl-3,5-heptanedione chelates of praseodimium and holmium

  • Claudio Airoldi
  • Luiz S. SantosJr.


The general thermochemical reaction LnCl3·6H2O(c)+3Hthd(1)+73.92H2O(1) = Ln(thd)3(c) +3HCl·26.64H2O(aq); ΔrHm (Ln = Pr, Ho and thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) was employed to determine through solution-reaction calorimetry at 298.15 K the standard molar enthalpies of formation of crystalline chelates, −2434.3±11.5 (Pr) and −2384.8±11.5 (Ho) kJ mol−1. These values and the corresponding molar enthalpies of sublimation enabled the determination of the standard molar enthalpies of chelates in the gaseous phase. From these values the mean enthalpies of the lanthanide-oxygen bond, 265±10 (Pr) and 253±10 (Ho) kJ mol−1 were calculated.

Key words

Thermochemistry 2,2,6,6-tetramethyl-3,5-heptanedione mean enthalpy β-diketonates lanthanide elements lanthanide-oxygen bond 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Mehrotra, R. C.; Bohra, R.; Gaur, D. P.Metal β-Diketonates and Allied Derivatives; Academic: London, 1978.Google Scholar
  2. 2.
    Joshi, K. C.; Pathak, V. N.Coord. Chem. Rev. 1983,48, 101.Google Scholar
  3. 3.
    Mortimer, C. T.Rev. Inorg. Chem. 1984,6, 233.Google Scholar
  4. 4.
    Ribeiro da Silva, M. A. V. InThermochemistry and Its Applications to Chemical and Biochemical Systems; Ribeiro da Silva, M. A. V., Ed.; Nato ASI Series; Reidel: Dordrecht, 1984.Google Scholar
  5. 5.
    Hill, J. O.Thermal Anal. Rev. 1991,20, 1.Google Scholar
  6. 6.
    Eisentrant, K. J.; Sievers, R. E.Inorg. Synth. 1968,11, 94.Google Scholar
  7. 7.
    Airoldi, C.; Digiampietri, E. A.J. Chem. Thermodyn. 1992,24, 33.Google Scholar
  8. 8.
    Wagman, D. D.; Evans, W. H.; Parker, V. B.; Schumm, R. H.; Halow, I.; Bailey, S. W.; Churney, K. L.; Nuttall, R. L.J. Phys. Chem. Ref. Data 1982, 11, suppl. 2.Google Scholar
  9. 9.
    Ferrāo, M. L. C. C. H.; Ribeiro da Silva, M. A. V.; Suradi, S.; Pilcher, G.; Skinner, H. A.J. Chem. Thermodyn. 1981,13, 567.Google Scholar
  10. 10.
    Irving, R. J.; Ribeiro da Silva, M. A. V.J. Chem. Soc., Dalton Trans. 1975, 798.Google Scholar
  11. 11.
    de Souza, A. G.; de Souza, J. H.; Airoldi, C.J. Chem. Soc., Dalton. Trans. 1991, 1751.Google Scholar
  12. 12.
    Sicre, J. E.; Dubois, J. T.; Eisentrant, K. J.; Sievers, R. H.J. Am. Chem. Soc. 1969,18, 3476.Google Scholar
  13. 13.
    Cavell, K. J.; Connor, J. A.; Pilcher, G.; Ribeiro da Silva, M. A. V.; Ribeiro da Silva, M. D. M. C.; Skinner, H. A.; Virrnani, Y.; Zafarani-Moattar, M. T.,J. Chem. Soc., Faraday Trans, I 1981,77, 1585.Google Scholar
  14. 14.
    Ribeiro da Silva, M. A. V.; Reis, A. M. M. V.J. Chem. Thermodyn. 1983,15, 957.Google Scholar
  15. 15.
    Volpe, P. L. O.; Chagas, A. P.; Airoldi, C.J. Inorg. Nucl. Chem. 1980,42, 1321.Google Scholar

Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • Claudio Airoldi
    • 1
  • Luiz S. SantosJr.
    • 1
  1. de QuímicaUniversidade Estadual de CampinasSão PauloBrasil

Personalised recommendations