Structures of five salt forms of di­sulfonated monoazo dyes

The structures of five s-block metal salt forms of three di­sulfonated monoazo dyes are presented. These are poly[di-μ-aqua-di­aqua­[μ(4)-3,3′-(di­azane-1,2-di­yl)bis­(benzene­sulfonato)]disodium(I)], [Na(2)(C(12)H(8)N(2)O(6)S(2))(H(2)O)(4)](n), (I), catena-poly[[tetra­aqua­calcium(II)]-μ-3,3′-(di­azane-1,2-di­yl)bis­(benzene­sulfonato)], [Ca(C(12)H(8)N(2)O(6)S(2))(H(2)O)(4)](n), (II), catena-poly[[[di­aqua­calcium(II)]-μ-2-(4-amino-3-sulfonato­phen­yl)-1-(4-sulfonato­phen­yl)diazenium] dihydrate], {[Na(C(12)H(10)N(3)O(6)S(2))(H(2)O)(2)]·2H(2)O}(n), (III), hexa­aqua­magnesium bis­[2-(4-amino-3-sulfonato­phen­yl)-1-(4-sulfonato­phen­yl)diazenium] octa­hydrate, [Mg(H(2)O)(6)](C(12)H(10)N(3)O(6)S(2))(2)·8H(2)O, (IV), and poly[[{μ(2)-4-[2-(4-amino-2-methyl-5-meth­oxy­phen­yl)diazen-1-yl]benzene-1,3-di­sulfonato}di-μ-aqua-di­aqua­barium(II)] dihydrate], {[Ba(C(14)H(13)N(3)O(7)S(2))(H(2)O)(4)]·2H(2)O}(n), (V). Compound (III) is that obtained on crystallizing the commercial dyestuff Acid Yellow 9 [74543-21-8]. The Mg species is a solvent-separated ion-pair structure and the others are all coordination polymers with bonds from the metal atoms to sulfonate groups. Compound (I) is a three-dimensional coordination polymer, (V) is a two-dimensional coordination polymer and both (II) and (III) are one-dimensional coordination polymers. The coordination behaviour of the azo ligands and the water ligands, the dimensionality of the coordination polymers and the overall packing motifs of these five structures are contrasted to those of mono­sulfonate monoazo congers. It is found that (I) and (II) adopt similar structural types to those of mono­sulfonate species but that the other three structures do not.