catena-Poly[[aqua­lithium(I)]-μ-3-carb­oxy-5,6-di­methyl­pyrazine-2-carboxyl­ato-κ(4) O (2),N (1):O (3),N (4)]

The asymmetric unit of the title compound, [Li(C(8)H(6)N(2)O(4))(H(2)O)](n), comprises three Li cations, two of which are located on a twofold rotation axis, two carboxylate anions and three water mol­ecules, of which two are situated on the twofold rotation axis being aqua ligands. Both carboxylate anions are in μ(2)-bridging mode. All Li ions show a trigonal–bipyramidal coordination mode; the two located in special positions are bridged through N,O-bonding sites generating a polymeric ribbon along the c-axis direction. The Li cation in a general position creates an independent polymeric ribbon through N,O-bonding sites of the two symmetry-related ligands; the trigonal–bipyramidal coordination is completed by an aqua ligand. In both carboxylate anions, a carboxyl­ate and a carb­oxy­lic acid group form an intra­molecular hydrogen bond. The polymeric ribbons running along [001] are inter­connected by hydrogen bonds in which the water mol­ecules act as donors and carboxyl­ate O atoms act as acceptors, giving rise to a three-dimensional architecture.