Poly[tetra-μ-aqua-diaqua-tetra-kis-[μ-(E)-2-nitro-cinnamato]tetra-rubidium].
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 octa-hedral stereochemistry and two of which have a distorted RbO(6) octa-hedral coordination. The bonding about both the seven-coordinate cations is similar, comprising one monodentate water mol-ecule together with three bridging water mol-ecules and three carboxyl-ate 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 mol-ecule and four bridging carboxyl-ate 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 inter-layer water O-H⋯O hydrogen-bonding associations to water, carboxyl and nitro O-atom acceptors, together with weak inter-ring π-π inter-actions [minimum ring centroid-centroid separation = 3.5319 (19) Å].
Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001,  Australia.
Graham
G
Smith
Urs D
UD
Wermuth