catena-Poly[[nickel(II)-μ-1,3-dimethyl-2,6-dioxo-7H-purinato-κ(2) N (7):N (9)] hydroxide]

The title complex, {[Ni(C(7)H(7)N(4)O(2))]OH}(n), has been prepared through hydro­thermal synthesis. The asymmetric unit contains one [Ni(TH)](+) cation (TH is the theophylline anion) and one hydroxide anion. The Ni(2+) ion is coordinated by two N atoms from two neighboring theophylline anions. The alternating linkage of the Ni(2+) cation and theophylline anion results in a one-dimensional chain along the [010] direction. Intermolec­ular O—H⋯O hydrogen bonds are present n the crystal structure.