Twelve 4-(4-meth­oxy­phen­yl)piperazin-1-ium salts containing organic anions: supra­molecular assembly in one, two and three dimensions

Twelve 4-(4-meth­oxy­phen­yl)piperazin-1-ium salts containing organic anions have been prepared and structurally characterized. The monohydrated benzoate, 4-fluoro­benzoate, 4-chloro­benzoate and 4-bromo­benzoate salts, C(11)H(17)N(2)O(+)·C(7)H(5)O(2) (−)·H(2)O (I), C(11)H(17)N(2)O(+)·C(7)H(4)FO(2) (−)·H(2)O (II), C(11)H(17)N(2)O(+)·C(7)H(4)ClO(2) (−)·H(2)O (III), and C(11)H(17)N(2)O(+)·C(7)H(4)BrO(2) (−)·H(2)O (IV), respectively, are isomorphous and all exhibit disorder in the 4-meth­oxy­phenyl unit: the components are linked by N—H⋯O and O—H⋯O hydrogen bond to form chains of rings. The unsolvated 2-hy­droxy­benzoate, pyridine-3-carboxyl­ate and 2-hy­droxy-3,5-di­nitro­benzoate salts, C(11)H(17)N(2)O(+)·C(7)H(5)O(3) (−) (V), C(11)H(17)N(2)O(+)·C(6)H(4)NO(2) (−) (VI) and C(11)H(17)N(2)O(+)·C(7)H(3)N(2)O(7) (−) (VII), respectively, are all fully ordered: the components of (V) are linked by multiple N—H⋯O hydrogen bonds to form a chain of rings; those of (VI) are linked into a three-dimensional framework by a combination of N—H⋯O, C—H⋯O and C—H⋯N hydrogen bonds and those of (VII), where the anion has a structure reminiscent of the picrate anion, are linked into a three-dimensional array by N—H⋯O and C—H⋯O hydrogen bonds. The hydrogensuccinate and hydrogenfumarate salts, C(11)H(17)N(2)O(+)·C(4)H(5)O(4) (−) (VIII) and C(11)H(17)N(2)O(+)·C(4)H(3)O(3) (−) (IX), respectively, are isomorphous, and both exhibit disorder in the anionic component: N—H⋯O and O—H⋯O hydrogen bonds link the ions into sheets, which are further linked by C—H⋯π(arene) inter­actions. The anion of the hydrogenmaleate salt, C(11)H(17)N(2)O(+)·C(4)H(3)O(3) (−) (X), contains a very short and nearly symmetrical O⋯H⋯O hydrogen bond, and N—H⋯O hydrogen bonds link the anions into chains of rings. The ions in the tri­chloro­acetate salt, C(11)H(17)N(2)O(+)·C(2)Cl(3)O(2) (−) (XI), are linked into simple chains by N—H⋯O hydrogen bonds. In the hydrated chloranilate salt, 2C(11)H(17)N(2)O(+)·C(6)Cl(2)O(4) (2−)·2H(2)O (XII), which crystallizes as a non-merohedral twin, the anion lies across a centre of inversion in space group P2(1)/n, and a combination of N—H⋯O and O—H⋯O hydrogen bonds generates complex sheets. Comparisons are made with the structures of some related compounds.