A tetrahedrally coordinated AgI and NiII complex with a two-dimensional framework containing one-dimensional helical chains

The title complex, poly[bis(mu(6)-pyridine-2,6-dicarboxylato N-oxide) nickel(II)disilver(I)], [Ag2Ni(C7H3NO5)(2)](n) or [Ag2Ni( pydco)(2)](n) (H(2)pydco = pyridine-2,6-dicarboxylic acid N-oxide), has a two-dimensional sheet structure. The two carboxylate groups adopt two coordination modes. The Ni-II ion displays a distorted octahedral geometry, bonded to two carboxylate O atoms of two different pydco ligands and four O donors from another two ligands, i.e. two carboxylate O atoms and two N-oxide O atoms. The Ag-I ion adopts a tetrahedral coordination, linked by three O atoms of three different carboxylate groups and an N-oxide O atom.