Tetra­aqua­bis(5-carb­oxy-2-nitro­benzo­ato-κ O)manganese(II) dihydrate: a metal–water chain complex containing cyclic water tetra­mers.

In the title complex, [Mn(C₈H₄NO₆)₂(H₂O)₄]·2H₂O, cyclic water tetra­mers forming one-dimensional metal–water chains have been observed. The water clusters are trapped by the co-­operative association of coordination inter­actions and hydrogen bonds. The Mn^II ion resides on a center of symmetry and is in an octa­hedral coordination environment comprising two O atoms from two 5-carboxy-2-nitrobenzoate ligands and four O atoms from water mol­ecules. [ABSTRACT FROM AUTHOR]