Pentaaquatri-μ3-hydroxido-tris(iminodiacetato)-μ3-oxido-tetrahedro-calcium(II)tricobalt(III) 2.54-hydrate

Abstract

In the title compound, [CaCo3(C4H5NO4)3(OH)3O(H2O)5]·2.54H2O, the Co atom is octahedrally coordinated by one iminodiacetate (ida) dianion as a facial O,N,O′-tridentate ligand, two μ3-OH groups and one μ3-O ligand, forming an partial Co3O4 cubane cluster. This unit coordinates to a CaII cation in an O,O′,O′′-tridentate fashion, generating a distorted CaCo3O4 cubane-type cluster. The Ca—μ3-O distances [2.429 (5)–2.572 (6) Å] are much longer than the Co—μ3—O bonds [1.895 (5)–1.941 (5) Å]. The CaII cation is also coordinated by five water molecules with Ca—O distances in the range 2.355 (6)–2.543 (6) Å. There are three additional uncoordinated water molecules in the asymmetric unit, the occupancy of which refined to 0.54 (3). In H2O (or D2O), the title complex hydrolyses to Ca2+aq cations and [Co3(ida)3(μ2-OH)3(μ3-O)]2− anions.