1,2,3-Dithiazolyl and 1,2,35-Dithiadiazolyl Radicals as Spin-Bearing ...

In the early 1980’s a very important compound containing 12 manganese ions of
mixed valency (I-20) was discovered 125 and it was found that this acted as a single
molecule magnet. 126
While an in depth discussion of the chemistry and physics of single
molecule magnets is beyond the scope of this thesis, a brief overview of the
a
b
Figure 1-15. Compound I-20 a) Molecular structure. b) Coupling parameters.
intermolecular interactions in I-20 will aid in an understanding of intermolecular metalmetal
interactions. The compound shown in Figure 1-16 a is composed of eight Mn 3+
ions in a ring around the periphery, linked by bridging, acetate ligands and four Mn 4+
ions in a tetrahedral arrangement inside the ring, linked to one another and to the outer
ions by oxygen bridges. As the Mn 3+ ions have four unpaired electrons and the Mn 4+ ions
have three unpaired electrons, there are a very large number of possible spin states that
this molecule could potentially possess. Because of the complex structure of the
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