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Single Crystal EPR Spectra of $K_{12}[As_2W_18O_{66}Cu_3(H_2O)_2]{\cdot}11H_2O$, a Copper(II) Trimer


초록

Single crystal EPR spectra of K12[As2W18O66Cu3(H2O)2]${\cdot}$11H2O exhibit an orientation-dependent fine structure of an S = 3/2 system which is accounted for by the exchange and magnetic dipole interactions among the three Cu2+ ions. The hyperfine structure and the lines from the S = 1/2 manifolds have not been observed. The isotropic exchange parameters determined from the magnetic susceptibility data at 5-300 K are J1 = J2 =-7.8 cm-1. The magnitude of J values suggests that the unpaired electrons on three Cu2+ ions interact through a sequence of six bonds involving two tungsten atoms and three oxygen atoms. The Cu-Cu distance, 4.37 $\AA$, determined from the EPR spectra is considerably smaller than the value from the X-ray crystal structure determination, 4.76 $\pm$ 0.03 $\AA$, indicating that the point-dipole model underestimates the dipolar interaction.

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참고문헌

  1. Proc. Roy. Soc.(London) v.A214 Bleaney, A.;Bowers, K. D.
  2. Coord. Chem. Rev. v.13 Smith, T. D.;Pilbrow, J. R.
  3. J. Chem. Soc. Faraday Ⅱ Carr, S. G.;Smith, T. D.;Pilbrow, J. R.
  4. Acta Cryst. v.B38 Robert, F.;Leyrie, M.;Herve, G.
  5. J. Am. Chem. Soc. v.105 Siedle, A. R.;Padula, F.;Baranowski, J.;Goldstein, C.;Deangelo, M.;Kokszka, G. F.;Azevedo, L.;Venturini, E. L.
  6. Biological & Inorganic Copper Chemistry Kokoszka, G.;Padula, F.;Siedle, A. R.;Karlin, K. D.(ed.);Zubieta, J.(ed.)
  7. Inorg. Chem. v.30 Chaudhuri, P.;Winter, M.;Vedova, B. P. C. D.;Bill, E.;Trautwein, A.;Gehring, S.;Fleischhauer, P.;Nuber, B.;Weiss, J.
  8. Inorg. Chem. v.16 Brown, D. B.;Wasson, J. R.;Hall, J. W.;Hatfield, W. E.
  9. Inorg. Chem. v.12 Flynn, Jr. C. M.;Pope, M. T.
  10. Molecular Magnetism Kahn, O.
  11. Electron Paramagnetic Resonance Orton, J. W.
  12. J. Phys. C. v.4 Smith, S. R. P.;Owen, J.