Bulletin of the Korean Chemical Society

Korean Chemical Society (대한화학회)
권호 표지
DOI QR코드

DOI QR Code

Temperature-Dependent Redox Isomerism via Intramolecular Electron Transfer. Synthesis and Properties of Co(dmppz)₂(3,6-dbq)₂ (dmppz=1,4-dimethylpiperazine; 3,6-dbq=3,6-di-tert-butyl-1,2-quinone)

  • Published : 1997.06.20
Download PDF
⟨ Previous Next ⟩

Abstract

The preparation and characterization of $Co(dmppz)_2(3,6-dbq)_2$ (dmppz=1,4-dimethylpiperazine; 3,6-dbq=3,6-di-tert-butyl-1,2-quinone) are established. Temperature-dependent magnetic moments (100-400 K), variable-temperature IR, and electronic spectra are presented to show that the title complex exhibits an equilibrium via a catechol to cobalt intramolecular electron transfer. At temperatures below 350 K, the charge distribution of the complex is $Co^Ⅲ(dmppz)_2(3,6-dbsq)(3,6-dbcat)$ (3,6-dbsq=3,6-di-tert-butyl-1,2-semiquinonato; 3,6-dbcat=3,6-di-tert-butylcatecholato) whereas at the temperature beyond 390 K, the complex is predominantly Co^Ⅱ(dmppz)_2(3,6-dbsq)_2$ form in the solid state. At the temperature range of 350-390 K a mixture of Co(Ⅲ) and Co(Ⅱ) redox isomers exist at equilibrium. The transition temperature (Tc) of Co(Ⅲ)/Co(Ⅱ) in solution is approximately 50° lower than that in the solid state. In particular, thermal analysis on solid sample of the complex discloses that the transition for the Co(Ⅲ)/Co(Ⅱ) is accompanied by the change in heat content of 12.30 kcal/mol.

Keywords

References

  1. Chem. Brit. Bradley, D. D. C.
  2. Adv. Mater. v.4 Kahn, O.;Krober, J.;Jay, C.
  3. Nature v.364 Lindoy, L. F.
  4. New J. Chem. v.15 Zarembowitch, J.;Kahn, O.
  5. Angew. Chem., Int. Ed. Engl. v.31 Sal Beck, J.;Komissarov, V. N.;Minkin, V. I.;Daub, J.
  6. J. Am. Chem. Soc. v.110 Aviram, A.
  7. J. Am. Chem. Soc. v.112 Hush, N. S.;Wong, A. T.;Bacskay, G. B.;Reimers, J. R.
  8. New J. Chem. v.16 Gourdon, A.
  9. J. Am. Chem. Soc. v.115 Krober, J.;Codjovi, E.;Kahn, O.;Groliere, F.;Jay, C.
  10. Chem. Mater. v.6 Krober, J.;Audiere, J.-P.;Claude, R.;Codjovi, E.;Kahn, O.;Hassnoot, J. G.;Groliere, F.;Jay, C.;Bouseksou, A.;Linares, J.;Varret, F.;Gonthier-Vassal, A.
  11. Chem. Phy. Lett. v.160 Launay, J. P.;Malgorzata, S.;Leydier, L.;Gourdon, A.;Amouyal, E.;Boillot, M. L.;Heisel, F.;Miehe, J. A.
  12. Molecular Electronic Devices Ⅲ Launay, J. P.;Woitellier, S.;Sowinska, M.;Tourel, M.;Joachim, C.
  13. Inorg. Chem. v.30 Haga, M.;Ano, T.;Kano, K.;Yamabe, S
  14. J. Am. Chem. Soc. v.102 Buchanan, R. M.;Pierpont, C. G.
  15. J. Am. Chem. Soc. v.115 Adams, D. M.;Dei, A.;Rheingold, A. L.;Hendrickson, D. N.
  16. J. Am. Chem. Soc. v.116 Jung, O.-S.;Pierpont, C. G.
  17. J. Am. Chem. Soc. v.116 Jung, O.-S.;Pierpont, C. G.
  18. Inorg. Chim. Acta v.226 Attia, A. S.;Jung, O.-S.;Pierpont, C. G.
  19. Inorg. Chem. v.33 Jung, O.-S.;Pierpont, C. G.
  20. Izv. Akad. Nauk SSSR Belostotskaya, I. S.;Komissarova, N. L.;Dzhuaryan, E. V.;Ershov, V. V.
  21. Bull. Korean Chem. Soc. v.16 Jo, D. H.;Jeong, J. H.;Yeo, H. J.;Sohn, Y. S.;Jung, O.-S.
  22. Syn. Met. v.71 Jung, O.-S.;Lee, Y.-A.;Pierpont, C. G.
  23. Angew. Chem., Int. Ed. Engl. v.35 Jung, O.-S.;Jo, D. H.;Lee, Y.-A.;Sohn, Y. S.;Pierpont, C. G.
  24. Angew. Chem., Int. Ed. Engl. v.32 Adams, D. M.;Dei, A.;Rheingold, A. L.;Hendrickson, D. N.