catena-Poly[[[bis­[μ-3-(4-carb­oxy­phen­oxy)propionato]-κ(3) O (1),O (1′):O (1);κ(3) O (1):O (1),O (1′)-bis­[aqua­(N,N-dimethyl­formamide-κO)cadmium]]-μ-4,4′-bipyridine-κ(2) N:N′] dinitrate]

In the title coordination polymer, {[Cd(2)(C(10)H(9)O(5))(2)(C(10)H(8)N(2))(2)(C(3)H(7)NO)(2)(H(2)O)(2)](NO(3))(2)}(n), the 3-(4-carb­oxy­phen­oxy)propionate monoanion O,O′-chelates to a Cd(II) cation through the aliphatic carboxyl­ate end. One of these O atoms is also connected to the metal cation from an inversion-related metal atom. The five O atoms bonded to the metal centre form a penta­gon, above and below which are located the N atoms of the 4,4′-bipyridine mol­ecules. The polycationic ribbon propagates along the b axis of the unit cell. The (aromatic) carboxyl end of the monoanion connects adjacent ribbons into a layer motif in the (102) plane. The nitrate ions are hydrogen bonded to the layer. The geometry of the Cd(II) atom is a trans-N(2)O(5)Cd penta­gonal bipyramid.