Poly[tetra-μ-aqua-diaqua­tetra­kis­[μ-(E)-2-nitro­cinnamato]tetra­rubidium]

In the structure of the title compound, [Rb(4)(C(9)H(6)NO(4))(4)(H(2)O)(6)](n), the asymmetric unit comprises four rubidium cations, two of which have an RbO(7) coordination polyhedron with a monocapped distorted octa­hedral stereochemistry and two of which have a distorted RbO(6) octa­hedral coordination. The bonding about both the seven-coordinate cations is similar, comprising one monodentate water mol­ecule together with three bridging water mol­ecules and three carboxyl­ate O-atom donors, two of which are bridging. The environments around the six-coordinate cations are also similar, comprising a monodentate nitro O-atom donor, a bridging water mol­ecule and four bridging carboxyl­ate O-atom donors [overall Rb—O range = 2.849 (2)–3.190 (2) Å]. The coordination leads to a two-dimensional polymeric structure extending parallel to (001), which is stabilized by inter­layer water O—H⋯O hydrogen-bonding associations to water, carboxyl and nitro O-atom acceptors, together with weak inter-ring π–π inter­actions [minimum ring centroid–centroid separation = 3.5319 (19) Å].