Creatinium hydrogen oxalate

The crystal structure of the title compound, C₄H₁₀N₃O₂⁺·C₂HO₄⁻, is stabilized by N—H...O and O—H...O hydrogen bonds. The anions are connected by an O—H...O hydrogen bond, leading to C(5) chain extending along c axis. The cations are dimerized around the corners of the unit cell, leading to an R₂²(14) ring motif. This leads to a cationic mol­ecular aggregation at x = 0 or 1 and an anionic mol­ecular aggregation at x = 1/2.

4-Chloro­anilinium 3-carb­oxy­prop-2-enoate

In the title compound, C₆H₇ClN⁺·C₄H₃O₄⁻, the cations and anions lie on mirror planes and hence only half of the mol­ecules are present in the asymmeric unit. The 4-chloro­anilinium cation and hydrogen maleate anion in the asymmetric unit are each planar and are oriented at an angle of 15.6 (1)° to one another and perpendicular to the b axis. A characterestic intra­molecular O—H...O hydrogen bond, forming an S(7) motif, is observed in the maleate anion. In the crystal, the cations and anions are linked by N—H...O hydrogen bonds, forming layers in the ab plane. The aromatic rings of the cations are sandwiched between hydrogen-bonded chains and rings formed through the amine group of the cation and maleate anions, leading to alternate hydro­phobic (z = 0 or 1) and hydro­philic layers (z = 1/2) along the c axis.

Creatininium 2-chloro­acetate

In the title compound (systematic name: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 2-chloro­acetate), C₄H₈N₃O⁺·C₂H₂ClO₂⁻, the mol­ecular aggregations are stabil­ized through classical (N—H...O) and non-classical (C—H...O and C—H...N) hydrogen-bonding inter­actions. The cations are linked to the anions, forming ion pairs through two N—H...O bonds that produce characteristic R₂²(8) ring motifs. These cation–anion pairs are connected through another N—H...O hydrogen bond, leading to an R₄²(8) ring motif. Further weak C—H...N inter­actions link the mol­ecules along the a axis, while other C—H...O inter­actions generate zigzag chains extending along b.

1-(2,4-Dinitro­phen­yl)-3-phenyl-4-phenyl­sulfanyl-1H-pyrazole

In the title mol­ecule, C₂₁H₁₄N₄O₄S, the pyrazole ring forms dihedral angles of 45.6 (1), 87.7 (1) and 27.4 (1)° with the phenyl, sulfur-substituted benzene and nitro-substituted benzene rings, respectively. In the crystal, mol­ecules are connected by weak C—H...O and C—H...N hydrogen bonds into layers parallel to (010).