The reaction of the triangular complex [Fe2MnO(HCCl2COO)6(THF)2H2O] [1]
with KMnO4 in 60% CH3COOH gives the heterometalic dodecanuclear, mixedcarboxylate
cluster [FenMn12-nO12(CH3COO)12(HCCl2COO)4(H2O)4] ⋅ H2O
(1). Complex 1 crystallizes in tetragonal space group I-4, whit the following unit

cell parameters: a=17.210(2) b=17.210(2) c=12.655(4) Å. The central part of
the neutral molecule is built of [MnIV
4O4]8+ cubane core, surrounded by the eight
((8-x)FeIII and xMnIII) atoms. All MIII atoms exhibit an octahedral coordination
with two different sets of hexa-oxygen environments. The assembling of the 12
metal atoms in the cluster occurs through eight μ3-oxygen atoms and sixteen
syn-syn bidentate-bridged carboxylate ligands. Four of these ligands are the
residues of dichloroacetic acid, while the rest are the residues of acetic acid.
Each coordinated water molecule is involved in to the formation of two H-binds:
one of them with solvate water molecule and another one with carboxylate
oxygen coordinated to the neighboring iron atom, which sustains additionally
M1… M2 linkage.
[1] Shova, S.G., Prodius, D.N., Mereacre, V.M., Simonov, Yu., Lipkowski J.,
Turta, C.I.: Inorg. Chem. Comm. (2004) 7, № 2, 293-295.