Poly[μ(2)-aqua-μ(2)-(pyrazine-2-carboxyl-ato)-lithium].

The structure of the title compound, [Li(C(5)H(3)N(2)O(2))(H(2)O)](n), contains an Li(I) ion with a distorted trigonal-bipyramidal coordination environment involving the N and O atoms of pyrazine-2-carboxyl-ate ligands with a bridging carboxyl-ate group, and two aqua O atoms also in a bridging mode. The symmetry-related Li(I) ions bridged by a carboxyl-ate O atom and a coordinating water O atom form an Li(2)O(2) unit with an Li⋯Li distance of 3.052 (4) Å, which generates mol-ecular ribbons propagating in the c-axis direction. The ribbons are held together by a network of O-H⋯O hydrogen bonds in which the coordinating water mol-ecules act as donors and the carboxyl-ate O atoms as acceptors.