Catena-Poly[[(3,5-dicarb-oxy-pyrazine-2,6-dicarboxyl-ato-?O,N,O)lithium(I)]-?-aqua-[triaqua-lithium(I)]-?-aqua].

ABSTRACT: The title coordination polymer, [Li(2)(C(8)H(2)N(2)O(8))(H(2)O)(5)](n) contains two symmetry-independent Li(+) ions; one is coordin-ated by five water O atoms, the other by an O,N,O'-tridentate doubly deprotonated pyrazine-2,3,5,6-tetra-carboxyl-ate ligand and two water O atoms. Water mol-ecules bridge adjacent Li(+) ions into ribbons propagating in [100]; an alternative analysis of the structure considers it to contain alternating [Li(C(8)H(2)N(2)O(8))(H(2)O)(2)](-) anions and [Li(H(2)O)(3)](+) cations. In the polymeric model, both lithium ions show distorted trigonal-bipyramidal coordination geometries. Within the ligand, the carboxyl H atoms participate in short, almost symmetric O?H?O hydrogen bonds in which the non-coordinated carboxyl-ate O atoms are donors and acceptors. In the crystal, the ribbons inter-act via a network of O-H?O hydrogen bonds in which the coordinated water mol-ecules act as donors and ligand carboxyl-ate O atoms as acceptors.

SUBMITTER: Starosta W 

PROVIDER: S-EPMC3011810 | biostudies-other | 2010

REPOSITORIES: biostudies-other