Exchange Interactions in a Dinuclear Manganese (II) Complex with   Cyanopyridine-N-oxide Bridging Ligands
  The structure and magnetic properties of oligonuclear manganese complex [Mn(hfa)2cpo]2 (where hfa is hexafluoroacetylacetonate dehydrate and cpo is 4-cyanopyridine-N-oxide) are presented. In the unit cell, the dinuclear molecules are well isolated from each other. The non-monotonous dependence of magnetic susceptibility is explained in terms of the hierarchy of exchange parameters by using exact diagonalization. The thermodynamic behavior of pure cpo and [Mn(hfa)2(cpo)]2 is simulated numerically in a dimer approximation by an extrapolation to spin S = 5/2. The Mn-Mn exchange integral is evaluated. 
A.S. Markosyan, I.Yu. Gaidukova, A.V. Ruchkin, A.O. Anokhin, V.Yu.   Irkhin, M. V. Ryazanov, N.P. Kuz'mina, and V.N. Nikiforov
cond-mat.mtrl-sci