Overlap Density in Binuclear Complexes; A Topological Approach of the Exchange Interaction

  • Olivier Kahn
  • Marie France Charlot
Part of the Quantum Theory Chemical Reactions book series (QTCR, volume 2)


An approach of the exchange interaction phenomenon in polynuclear complexes grounded on the concepts of magnetic orbitals and of overlap density between these magnetic orbitals is proposed. The aim of this work is to show how these simple concepts can lead to a prevision of the variations of the JAFntiferromagnetic and the Jf ferromagnetic contributions to the J exchange parameter (J = Jaf + Jf) versus small structural changes in closely related complexes. In section 2, it is demonstrated that in binuclear complexes without direct metal-metal interaction, the exchange interaction can be studied by focusing on the overlap density between the magnetic orbitals around the bridging atoms. The section 3 deals with copper (II) dimers with the
network; the influences of both the bridging angle θ defined as θ=2 CuXX and the dihedral angle D between the two CuXX planes are studied. The section 4 is devoted to Cu(II) — VO(II) and Cu(II)-low spin CO(II) heterobinuclear complexes in which a strict orthogonality of the magnetic orbitals is realized. The strong ferromagnetic coupling experimentally observed in CuV0(fsa)2en, CH3OH [H4(fsa)2en = N, N’-(2-hydroxy, 3-carboxy benzilidene) 1, 2-diaminoethane] is explained from the overlap density map for the appropriate model complex. A prospective study of the influence of an axial ligand coming near the Co(II) ion on the magnetic properties of Cu(II)- low spin Co(II) complexes is presented.


Exchange Interaction Axial Ligand Binuclear Complex Polynuclear Complex Spin Triplet 
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Copyright information

© D. Reidel Publishing Company 1980

Authors and Affiliations

  • Olivier Kahn
    • 1
  • Marie France Charlot
    • 1
  1. 1.Laboratoire de Spectrochimie des Eléments de Transition, ERA n° 672Université de Paris SudOrsayFrance

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