Magnetic exchange interactions

Macrocyclic Schiff base compartmental ligands (750) (Robson-type ligands) derived from the [2 + 2] condensation of a 2,6-diformyl- or 2,6-diketo-substituted phenol and a diamine are very prominent in dinuclear Ni coordination chemistry.1901-1903 Particular interest lies in magnetic exchange interactions between the adjacent metal ions as well as in bioinorganic chemistry, where such dinuclear complexes have been proposed as synthetic analogues for bimetallosites. 

Anderson, P.W. 1963. Theory of magnetic exchange interaction exchange in insulators and semiconductors. In Solid State Physics Volume 14, eds. F. Seitz and D. Turnbull. New York Academic Press. 

Finally, we discuss the effects of chalcogen (S to Se) substitution. Although in (EDS-TTF)2FeBr4 remarkably close Se---Br contacts exist between donor and anion layers, little magnetic exchange interaction exists between the magnetic anions. The molecular orbital calculation reveals that the contribution of Se 4p orbital to the HOMO of the EDS-TTF molecule is considerably smaller than the contribution of... 

The Schiff base complex [SrL](BPh4)2 (L = (188)) was obtained by an in situ metal template procedure." This species undergoes a transmetallation reaction in dry ethanol to yield [Mn2NCS4] (L = (188)). No evidence for a magnetic exchange interaction was observed in this case. 

Evidence for species such as the dihydroxy-bridged dimers exists for ferric complexes of picolinate and 2,6 dicarboxylatopyridine. Complexes of the type [(PA)2Fe(OH)2]2, 13b, and (H20)LFe(0H)2FeL(0H2), where L = 2,6-dicarboxylato(4-X)pyridine, (X = H, NMe2, OH), have been structurally and spectroscopically characterized (41-43). The magnetic exchange interactions in these systems are characterized by weak antiferromagnetic coupling values of J = — 8 cm-1 were reported for 13b. 

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