The structures of eleven (4-phenyl)piperazinium salts containing organic anions

Eleven (4-phen­yl)piperazinium salts containing organic anions have been prepared and structurally characterized, namely, 4-phenyl­piperazin-1-ium 4-fluoro­benzoate monohydrate, C10H15N2+·C7H4FO2−·H2O, 1; 4-phenyl­piperazin-1-ium 4-bromo­benzoate monohydrate, C10H15N2+·C7H4BrO2−·H2O, 3; 4-phenyl­piperazin-1-ium 4-iodo­benzoate, C10H15N2+·C7H4IO2−, 4; 4-phenyl­piperazin-1-ium 4-nitro­benzoate, C10H15N2+·C7H4NO4−, 5; 4-phenyl­piperazin-1-ium 3,5-di­nitro­salicylate, C10H15N2+·C7H3N2O7−, 6; 4-phenyl­piperazin-1-ium 3,5-di­nitro­benzoate, C10H15N2+·C7H3N2O6−, 7; 4-phenyl­piperazin-1-ium picrate, C10H15N2+·C6H2N3O7−, 8; 4-phenyl­piperazin-1-ium benzoate monohydrate, C10H15N2+·C7H5O2−·H2O, 9; 4-phenyl­piperazin-1-ium p-toluene­sulfonate, C10H15N2+·C7H7O3S−, 10; 4-phenyl­piperazin-1-ium tartarate monohydrate, C10H15N2+·C4H5O6−·H2O, 11; and 4-phenyl­piperazin-1-ium fumarate, C10H15N2+·C4H3O4−, 12. Compounds 1 and 3–12 are all 1:1 salts with the acid proton transferred to the phenyl­piperaizine basic N atom (the secondary amine) with the exception of 3 where there is disorder in the proton position with it being 68% attached to the base and 32% attached to the acid. Of the structures with similar stoichiometries only 3 and 9 are isomorphous. The 4-phenyl substituent in all cases occupies an equatorial position except for 12 where it is in an axial position. The crystal chosen for structure 7 was refined as a non-merohedral twin. There is disorder in 5, 6, 10 and 11. For both 5 and 6, a nitro group is disordered and was modeled with two equivalent orientations with occupancies of 0.62 (3)/0.38 (3) and 0.690 (11)/0.310 (11), respectively. For 6, 10 and 11, this disorder is associated with the phenyl ring of the phenyl­piperazinium cation with occupancies of 0.687 (10)/0.313 (10), 0.51 (7)/0.49 (7) and 0.611 (13)/389 (13), respectively. For all salts, the packing is dominated by the N—H⋯O hydrogen bonds formed by the cation and anion. In addition, several structures contain C—H⋯π (1, 3, 4, 8, 9, 10, and 12) and aromatic π–π stacking inter­actions (6 and 8) and one structure (5) contains a –NO2⋯π inter­action. For all structures, the Hirshfeld surface fingerprint plots show the expected prominent spikes as a result of the N—H⋯O and O—H⋯O hydrogen bonds

4-Chloro-N-(3,5-dimethyl­phen­yl)benzene­sulfonamide

The asymmetric unit of the title compound, C14H14ClNO2S, contains two independent mol­ecules, which are twisted at the S atoms with C—SO2—NH—C torsion angles of −69.4 (7)° and 66.0 (8)°. The sulfonyl and the anilino benzene rings are tilted relative to each other by 49.0 (4) and 61.7 (3)° in the two mol­ecules. In the crystal, the mol­ecules are linked into chains by N—H⋯O hydrogen bonds

4-Chloro-N-(2,6-dimethyl­phen­yl)benzene­sulfonamide

In the title compound, C14H14ClNO2S, the amido H atom orients itself away from both the ortho-methyl groups in the adjacent aromatic ring. The mol­ecule is twisted at the S atom with an C—SO2—NH—C torsion angle of −69.9 (2)°. The two aromatic rings are tilted relative to each other by 31.9 (1)°. In the crystal, the mol­ecules are packed into zigzag chains along the b axis via inter­molecular N—H⋯O hydrogen bonds

4-Chloro-N-(3-chloro­phen­yl)benzene­sulfonamide

In the crystal of the title compound, C12H9Cl2NO2S, the mol­ecule is twisted at the S atom with a C—SO2—NH—C torsion angle of −58.4 (3)°. Furthermore, the N—H bond in this segment is anti to the meta-chloro group. The dihedral angle between the aromatic rings is 77.1 (1)°. The crystal structure features inversion-related dimers linked by N—H⋯O hydrogen bonds

N-(4-Methyl-2-nitro­phen­yl)succinamic acid

In the title compound, C11H12N2O5, the conformation of the N—H bond in the amide segment is syn to the ortho-nitro group in the benzene ring. The amide C=O and the carboxyl C=O of the acid segment are syn to each other and both are anti to the H atoms on the adjacent –CH2 groups. Furthermore, the C=O and O—H bonds of the acid group are in syn positions with respect to each other. The dihedral angle between the benzene ring and the amide group is 36.1 (1)°. The amide H atom shows bifurcated intra­molecular hydrogen bonding with an O atom of the ortho-nitro group and an inter­molecular hydrogen bond with the carbonyl O atom of another mol­ecule. In the crystal, the N—H⋯O(C) hydrogen bonds generate a chain running along the [100] direction. Inversion dimers are formed via a pair of O—H⋯O(C) interactions, that form an eight-membered hydrogen-bonded ring involving the carboxyl group

2-Chloro-N-[(2-methyl­phen­yl)sulfon­yl]acetamide

In the title compound, C9H10ClNO3S, the amide H atom is syn with respect to the ortho-methyl group in the benzene ring and the C—S—N—C torsion angle is −66.9 (2)°. An intra­molecular N—H⋯Cl hydrogen bond occurs. The crystal structure features inversion-related dimers linked by pairs of N—H⋯O hydrogen bonds

N-(4-Methyl­phenyl­sulfon­yl)succinamic acid

In the crystal structure of the title compound, C11H13NO5S, the amide C=O and the carboxyl C=O groups of the acid segment orient themselves away from each other. The dihedral angle between the benzene ring and the amide group is 69.0 (2)°. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link the mol­ecules into layers parallel to the bc plane

N-(2-Chloro-4-methyl­phen­yl)succinamic acid

In the title compound, C11H12ClNO3, the N—C=O fragment is twisted from the plane of the attached benzene ring by 48.39 (12)°. The carb­oxy­lic acid group is involved in O—H⋯O hydrogen bonding, which links pairs of mol­ecules into centrosymmetric dimers. N—H⋯O hydrogen bonds link these dimers, related by translation along the a axis, into ribbons

N-(3,4-Dichloro­phen­yl)-4-methyl­benzene­sulfonamide

In the title compound, C13H11Cl2NO2S, the conformation of the N—C bond in the C—SO2—NH—C segment has gauche torsions with respect to the S=O bonds. The mol­ecule is bent at the S atom with a C—SO2—NH—C torsion angle of 64.3 (4)°. Furthermore, the conformation of the N—H bond and the meta-chloro group in the adjacent benzene ring are anti to each other. The two benzene rings are tilted relative to each other by 82.5 (1)°. In the crystal, mol­ecules are linked by pairs of N—H⋯O(S) hydrogen bonds, forming inversion dimers

N-(2,4,6-Trichloro­phen­yl)maleamic acid

In the crystal structure of the title compound, C10H6Cl3NO3, the conformation of the amide bond is trans. The C=O and O—H bonds of the acid group are in the relatively rare anti position to each other. This is a consequence of the intra­molecular O—H⋯O hydrogen bond donated to the amide carbonyl group stabilizing the mol­ecular structure. In the crystal, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into zigzag chains along the c axis