A tetra­hedrally coordinated Ag^I and Ni^II complex with a two-dimensional framework containing one-dimensional helical chains

The title complex, poly[bis­(μ₆-pyridine-2,6-dicarboxyl­ato N-­oxide)nickel(II)disilver(I)], [Ag₂Ni(C₇H₃NO₅)₂]_n or [Ag₂Ni(pydco)₂]_n (H₂pydco = 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.