Polymeric diaquatetrakis(-1,2-benzenedicarboxylato)di--nitrato-pentastrontium(II)

Colourless crystals of polymeric diaqua­tetrakis(μ-1,2-benzene­dicarboxyl­ato)di-μ-nitrato-pentastrontium(II), [Sr5(C8H4O4)4(NO3)2(H2O)2]n, crystallized at the phase boundary of an aqueous silica gel containing sodium phthalate (1,2-benzene­dicarboxyl­ate) and an aqueous solution of Sr(NO3)2. Three crystallographically distinct SrII ions, one located on a centre of symmetry, are connected by two crystallographically distinct phthalate anions, one nitrate anion and a water molecule, to form a layered coordination polymer. These layers, perpendicular to [001], are held together by weak interatomic forces, as no interlayer hydrogen bonds were found.