Manel Essid

Bis(1-methyl-piperazine-1,4-diium) di-μ-bromido-bis-[tetra-bromido-bismuthate(III)] dihydrate.

In the title hydrated salt, (C5H14N2)2[Bi2Br10]·2H2O, the complete [Bi2Br10]4− bioctahedron is generated by crystallographic inversion symmetry. The diprotonated piperazine ring adopts a chair conformation, with the methyl group occupying an equatorial position. In the crystal, the tetraanions and water molecules are linked by O—H⋯Br and O—H⋯(Br,Br) hydrogen bonds to generate [100] chains. The chains are crosslinked by N—H⋯Br, N—H⋯O and C—H⋯Br hydrogen bonds originating from the piperazinediium dications, thereby forming a three-dimensional network.

1-Methyl­piperazine-1,4-dium bis­(hydrogen oxalate)

In the crystal structure of the title compound, C5H14N2 2+·2HC2O4 −, the two crystallographically independent hydrogen oxalate anions are linked by strong intermolecular O—H⋯O hydrogen bonds, forming two independent corrugated chains parallel to the b axis. These chains are further connected by N—H⋯O and C—H⋯O hydrogen bonds originating from the organic cations, forming a three-dimensional network. The diprotonated piperazine ring adopts a chair conformation, with the methyl group occupying an equatorial position.

5-Amino-1H-1,2,4-triazol-4-ium hydrogen oxalate.

In the title salt, C2H5N4 +·C2HO4 −, the hydrogen oxalate anions form corrugated chains parallel to the c axis, linked by intermolecular O—H⋯O hydrogen bonds. The 5-amino-1H-1,2,4-triazol-4-ium cations are connected into centrosymmetric clusters via weak C—H⋯N hydrogen bonds forming nine-membered rings with an R 3 3(9) motif. These clusters are interconnected via anions through N—H⋯O hydrogen bonds, building a three-dimensional network.

4-Phenyl­piperazin-1-ium dihydrogen phosphate

The title compound, C10H15N2 +·H2PO4 −, is built up from 4-phenylpiperazin-1-ium cations and dihydrogen phosphate anions. The interconnection between two adjacent anions is assured by two strong O—H⋯O hydrogen bonds, which lead to the formation of infinite wave-like chains which spread along the a axis. The organic cations connect these chains via N—H⋯O hydrogen bonds. The crystal cohesion and stability are ensured by electrostatic and van der Waals interactions which, together with N—H⋯O and O—H⋯O hydrogen bonds, build up a two-dimensional network.

Propane-1,2-di­ammonium chromate(VI)

In the title molecular salt, (C3H12N2)[CrO4], each chromate anion accepts six N—H⋯O and C—H⋯O hydrogen bonds from nearby propane-1,2-diammonium cations. Three of the four O atoms of the chromate anion accept these bonds; the remaining Cr—O bond length is notably shorter than the others. In the crystal, the anions and cations stack in layers lying parallel to (100): the hydrogen-bonding pattern leads to a three-dimensional network.

N′-(2,4-Di­nitro­phen­yl)acetohydrazide monohydrate

In the crystal structure of the title compound, C8H8N4O5·H2O, the organic and lattice water molecules are linked together via N—H⋯O and O—H⋯O hydrogen bonds. A C—H⋯O interaction is also observed between the organic molecules. These hydrogen bonds and interactions lead to the formation of a three-dimensional network. An intramolecular N—H⋯O hydrogen bond also occurs. The dihedral angle between the acetyl group and the almost planar hydrazide moiety [maximum deviation from the least-squares plane is 0.209 (2) Å for one of the nitro O atoms] is 88.5 (3)°.