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, C11H17N2O+center dot C7H5O2-center dot H2O (I), C11H17N2O+center dot C7H4FO2-center dot H2O (II), C11H17N2O+center dot C7H4ClO2-center dot H2O (III), and C11H17N2O+center dot C7H4BrO2-center dot H2O (IV), respectively, are isomorphous and all exhibit disorder in the 4-methoxyphenyl unit: the components are linked by N-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bond to form chains of rings. The unsolvated 2-hydroxybenzoate, pyridine-3-carboxylate and 2-hydroxy-3,5-dinitrobenzoate salts, C11H17N2O+center dot C7H5O3- (V), C11H17N2O+center dot C6H4NO2- (VI) and C11H17N2O+center dot C7H3N2O7- (VII), respectively, are all fully ordered: the components of (V) are linked by multiple N -H center dot center dot center dot 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 center dot center dot center dot O, C-H center dot center dot center dot O and C-H center dot center dot center dot 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 center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds. The hydrogensuccinate and hydrogenfumarate salts, C11H17N2O+center dot C4H5O4- (VIII) and C11H17N2O+center dot C4H3O3- (IX), respectively, are isomorphous, and both exhibit disorder in the anionic component: N-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds link the ions into sheets, which are further linked by C-H center dot center dot center dot pi(arene) interactions. The anion of the hydrogenmaleate salt, C11H17N2O+center dot C4H3O3- (X), contains a very short and nearly symmetrical O center dot center dot center dot H center dot center dot center dot O hydrogen bond, and N-H center dot center dot center dot O hydrogen bonds link the anions into chains of rings. The ions in the trichloroacetate salt, C11H17N2O+center dot C2Cl3O2- (XI), are linked into simple chains by N -H center dot center dot center dot O hydrogen bonds. In the hydrated chloranilate salt, 2C(11)H(17)N(2)O(+)center dot C6Cl2O42-center dot 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 center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds generates complex sheets. Comparisons are made with the structures of some related compounds