Bis(2-meth-oxy-benzyl-ammonium) di-aqua-bis-(di-hydrogen diphosphato-κ(2) O,O')cobaltate(II) dihydrate.

The title compound, (C8H12NO)2[Co(H2P2O7)2(H2O)2]·2H2O, crystallizes isotypically with its Mn(II) analogue. It consists of alternating layers of organic cations and inorganic complex anions, extending parallel to (100). The complex cobaltate(II) anion exhibits -1 symmetry.

Bis(2,6-di-methyl-anilinium) di-aqua-bis-(di-hydrogen diphosphato-κ(2) O,O')cobaltate(II).

In the title compound, (C8H12N)2[Co(H2P2O7)2(H2O)2], the Co(2+) ion lies on a crystallographic inversion centre and adopts a slightly distorted octa-hedral CoO6 coordination geometry arising from two chelating diphosphate [H2P2O7](2-) ligands and two trans water mol-ecules. In the crystal, the components are linked by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds and weak aromatic π-π stacking [shortest centroid-centroid separation = 3.778 (2) Å] inter-actions.

2-Amino-pyrimidinium hydrogen sulfate.

In the crystal structure of the title compound, C(4)H(6)N(3) (+)·HSO(4) (-), hydrogen sulfate anions self-assemble through O-H⋯O hydrogen bonds, forming chains along the b axis, while the cations form centrosymmetric pairs via N-H⋯N hydrogen bonds. The 2-amino-pyrimidinium pairs are linked to the sulfate anions via N-H⋯O hydrogen bonds, forming a two-dimensional network parallel to (10[Formula: see text]). In addition, weak inter-molecular C-H⋯O contacts generate a three-dimensional network.

Tris(1,10-phenanthroline)cobalt(II) bis-(perrhenate) monohydrate.

In the title compound, [Co(C(12)H(8)N(2))(3)][ReO(4)](2)·H(2)O, the Co(II) atom is coordinated by three 1,10-phenanthroline ligands in a distorted octa-hedral arrangement. In the crystal, the components are linked by O-H⋯O, C-H⋯O and aromatic π-π stacking [shortest centroid-centroid separation = 3.659 (5) Å] inter-actions.

Bis(2-amino-3-nitro-pyridinium) dihydrogen-diphosphate.

The structure of the title compound, 2C(5)H(6)N(3)O(2) (+)·H(2)P(2)O(7) (2-), contains infinite (H(2)P(2)O(7) (2-))(n) layers stacked perpendicular to the a axis. The 2-amino-3-nitro-pyridinium cations are arranged in pairs and are anchored between these layers, linking them by N-H⋯O and C-H⋯O hydrogen-bonding and electrostatic inter-actions between anionic and cationic species to form a three-dimensional network.

2-Amino-3-nitro-pyridinium perchlorate.

The title compound, C(5)H(6)N(3)O(2) (+)·ClO(4) (-), is comprised of discrete perchlorate anions and 2-amino-3-nitro-pyridinium cations. The anion has a typical tetra-hedral geometry while the cation presents a nearly planar [maximum deviation = 0.007 (8) Å] pyridinium ring.

2-Amino-3-nitro-pyridinium perrhenate.

In the title mol-ecular salt, (C(5)H(6)N(3)O(2))[ReO(4)], the cations and tetrahedral anions are linked by trifurcated N-H⋯(O,O,O) and bifurcated N-H⋯(O,O) hydrogen bonds, as well as weak C-H⋯O inter-actions. This results in alternating corrugated inorganic and organic layers in the crystal.

2,6-Diethyl-anilinium dihydrogen phosphate-phospho-ric acid (1/1).

In the crystal structure of the title salt, C(10)H(16)N(+)·H(2)PO(4) (-)·H(3)PO(4), the H(2)PO(4) (-) and H(3)PO(4) components are connected into infinite chains extending along the b-axis direction by way of O-H⋯O links. These chains are also linked through O-H⋯O hydrogen bonds thus building up a supra-molecular two-dimensional framework extending parallel to (001). The organic cations cross-link the anionic layers by way of multiple N-H⋯O inter-actions, leading to a cohesive network.