Zigzag polymer chains in catena-poly[[[triaqua(isobutyrato-κO)magnesium(II)]-μ-isobutyrato-κ(2)O:O'] monohydrate].

The structure of the title compound, {[Mg(C4H7O2)2(H2O)3]·H2O}n, features one-dimensional ···(μ2-ib)Mg(μ2-ib)Mg··· zigzag chains (ib is isobutyrate) parallel to the c axis. The octahedral Mg environment is completed by three fac-oriented terminal water ligands, as well as one further monodentate end-on coordinated ib ligand. In the crystal structure, the hydrophobic ib groups are all oriented within one half of the coordination perimeter of each chain, whereas the water ligands, together with hydrogen-bonded noncoordinated solvent water molecules, define the other half. Along the a axis, neighbouring strands are oriented so that both the hydrophilic and hydrophobic sides are adjacent to each other. This results in an extensive hydrogen-bonding network within the hydrophilic areas, also involving an additional solvent water molecule per formula unit. There are van der Waals contacts between the aliphatic isopropyl groups of the hydrophobic areas.