Tetra­aqua­diazido­cobalt(II) 3,3′-dicarb­oxy­l­ato-1,1′-ethyl­enedipyridinium

The asymmetric unit of the title compound, [Co(N(3))(2)(H(2)O)(4)]·C(14)H(12)N(2)O(4), comprises half of the cobalt(II) complex mol­ecule and a half of the 3,3′-dicarboxyl­ato-1,1′-ethyl­enedipyridinium mol­ecule. The Co(II) atom is located on an inversion centre and hence the complex mol­ecule adopts a centrosymmetric trans-octa­hedral geometry. The zwitterionic organic mol­ecule is also centrosymmetric with the centre of the C—C bond of the ethyl­ene moiety coinciding with an inversion centre. The adduct of metal complex and organic mol­ecule is associated into a three-dimenional network through O—H⋯O hydrogen bonds.