Bis(2,2′-bipyridine-κ(2) N,N′)(3-methyl­benzoato-κ(2) O,O′)zinc 3-methyl­benzo­ate–3-methyl­benzoic acid–water (1/1/2)

The title compound, [Zn(C(8)H(7)O(2))(C(10)H(8)N(2))(2)](C(8)H(7)O(2))·C(8)H(8)O(2)·2H(2)O, is comprised of a Zn(2+) cation, two 2,2′-bipydine (bipy) ligands and one 3-methyl­benzoate anion (L (−)) together with one uncoordinating L (−) anion, one uncoordinating HL mol­ecule and two lattice water mol­ecules. The Zn(II) atom is coordinated by four N atoms of two bipy ligands and two O atoms from one L (−) ligand in a distorted octa­hedral geometry. Pairs of centrosymmetrically related complex mol­ecules form dimers via slipped π-stacking inter­actions between bipy ligands with an inter­planar distance of 3.470 (4) Å. The dimers are linked into supra­molecular chains along [111], via C—H⋯O hydrogen bonds. The uncoordinated L (−) anions, HL mol­ecules and water mol­ecules are connected with each other via O—H⋯O hydrogen bonds, forming chains between the metal complex chains and binding them together via C—H⋯O contacts. The resulting layers parallel to (010) are further assembled into a three-dimensional supra­molecular architecture through additional C—H⋯O inter­actions.