Metal-oxalato networks

Several X-ray crystal structures of two-dimensional oxalato-bridged mixed-metal networks have been reported since 1993. The first structural information on two-dimensional oxalates was obtained by Atovmyan et al who succeeded in growing single crystals of the compound... 

The first structure of a three-dimensional transition metal network incorporating the oxalate ion was that of [Ni(phen)3][KCo (ox)3] 2H20 (phen= 1,10-phenanthroline) reported by Snow and co-workers in 1971. The true dimensionality of this compound, however, went unrecognized during this period, and the potential of oxalate ions to form three-dimensional networks was not fully realized until 1993, when Decurtins et al. published the crystal structure of the iron(II)-oxalato complex with tris(2,2 -bipyridine)iron(II) cations. This compound has an overall stoichiometry of [Fe (bipy)3] [Fe 2(ox)3] " and forms a three-dimensional anionic polymeric network that is best described with the three-connected decagon network topology. A view of this anionic network is shown in Figure 43. 

The possibilities for linking paramagnetic metal ions via oxalate bridges in three-dimensional lattices and their possible applications in the field of molecule-based magnets have since provided the momentum for subsequent investigations into the self-assembly of three-dimensional oxalato-bridged metal complexes. Decurtins et al. reported the structural characterization of three additional compounds, one homometallic with the same network stoichiometry, [Mn 2(ox)3]2 ", as the Fe compound above, and two bimetallic with network stoichiometries of... 

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