Poly[[hepta-μ(2)-aqua-bis-(μ(2)-pyrazine-2-carboxyl-ato)dibarium] bis-(pyrazine-2-carboxyl-ate)]

Abstract

In the layered title coordination polymer, {[Ba(2)(C(5)H(3)N(2)O(2))(2)(H(2)O)(7)](C(5)H(3)N(2)O(2))(2)}(n), the coordination geometries around the two independent Ba(II) ions can be described as bicapped square-anti-prismatic [BaNO(9)] arrangements. A two-dimensional polymeric framework with (6,3) topology can be observed in the ac plane, the nodes being provided by Ba(II) ions and the connectors being N and O atoms belonging to pyrazine-2-carboxyl-ate ligands and O atoms of bridging water mol-ecules. Non-coordinating pyrazine-2-carboxyl-ate ions are located between the polymeric layers in the crystal and are interconnected through extensive O-H⋯N,O hydrogen bonding.

Fig. 1.

Coordination environment of BaII ions in the title complex. Non-hydrogen atoms are shown as 30% probability ellipsoids. Hydrogen atoms are omitted for clarity.

Fig. 2.

View of one two-dimensional layer structure along b axis in the title complex. Hydrogen atoms are omitted for clarity. Some redundant atoms are omitted for clarity.