catena-Poly[[[tetra­aqua­zinc(II)]-μ-1,4-bis­(1,2,4-triazol-1-yl)butane-κ(2) N (4):N (4′)] biphenyl-4,4′-dicarboxyl­ate]

The asymmetric unit of the polymeric title compound, {[Zn(C(8)H(12)N(6))(H(2)O)(4)](C(14)H(8)O(4))}(n) or {[Zn(BTB)(H(2)O)(4)](BPDC)}(n) [BTB is 1,4-bis­(1,2,4-triazol-1-yl)butane and H(2)BPDC is biphenyl-4,4′-dicarb­oxy­lic acid], contains half a [Zn(BTB)(H(2)O)(4)](2+) cation and half a BPDC anion, both ions lying about a crystallographic inversion centre. The crystal structure consists of zigzag polymeric cationic chains parallel to the c axis and uncoordinated anions linked into a three-dimensional supra­molecular architecture by O—H⋯O, C—H⋯O hydrogen bonds and C—H⋯π inter­actions.