title: catena-Poly[[(6-carb-oxy-pyrazine-2-carboxyl-ato)lithium]-μ-aqua].
abstract: The asymmetric unit of the title compound, [Li(C(6)H(3)N(2)O(4))(H(2)O)](n), contains an Li(I) ion with a distorted trigonal-bipyramidal coordination environment. It is chelated by a singly protonated ligand mol-ecule via its heterocyclic N atom, by two O aoms, each donated by an adjacent carboxyl-ate group, and is further coordinated by a water O atom which acts as a bridge, forming a mol-ecular ribbon. A proton attached to one of the carboxyl-ate O atoms is situated on an inversion centre and forms a short centrosymmetric hydrogen bond, generating mol-ecular layers parallel to the ac plane. These layers are held together by weak O-H⋯O hydrogen bonds in which the coordinated water mol-ecules act as donors, whereas carboxyl-ate O atoms are acceptors.
authors.affiliation: Institute of Nuclear Chemistry and Technology, ul. Dorodna 16, 03-195 Warszawa,  Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Starosta
authors.forename: Janusz
authors.initials: J
authors.lastname: Leciejewicz