In the title compound, C(10)H(6)N(2)O(5), the two fused rings are almost co-planar, with an r.m.s. deviation of 0.0163 Å. The nitro groups are oriented at dihedral angles of 2.62 (11) and 44.69 (11)° with respect to the plane of the parent fused rings. Intra-molecular O-H⋯O and C-H⋯O hydrogen bonds complete S(6) ring motifs. In the crystal, mol-ecules are linked into chains along [101] by inter...

The reaction of 3-amino-5-bromo-pyridine with N-iodo-succinimide in the presence of acetic acid produces the title compound, C(5)H(4)BrIN, with an iodo substituent in position 2 of the pyridine ring. The crystal structure features rather weak inter-molecular N-H⋯N hydrogen bonds linking the mol-ecules into chains along the z axis of the crystal.

In the title compound, C(7)H(6)ClN(3)O(4)S(2)·3C(5)H(5)N, (systematic name: 6-chloro-2H-1,2,4-benzothia-diazine-7-sulfonamide 1,1-dioxide pyridine tris-olvate), chloro-thia-zide forms a 1:3 solvate with pyridine. The crystal structure is stabilized by strong inter-molecular N-H⋯N hydrogen bonds.

In the title compound, C(23)H(17)N(5)·H(2)O, the pyrazole rings are slightly twisted from the central pyridine ring, forming dihedral angles of 5.3 (2) and 3.5 (2)°. The pyrazole and phenyl rings on each side of the pyridine ring are also approximately coplanar, making dihedral angles of 6.0 (2) and 4.5 (2)°. In the crystal structure, 2,6-bis-(3-phenyl-1H-pyrazol-5-yl)pyridine and water mol-ecu...

In the mol-ecule of the title compound, [Ni(C(5)H(4)NO(3)S)(2)(H(2)O)(4)], the Ni(II) cation is located on an inversion center and is coordinated by four water mol-ecules and two pyridine-3-sulfonate anions with an NiN(2)O(4) distorted octa-hedral geometry. The face-to-face separation of 3.561 (5) Å between parallel pyridine rings indicates the existence of weak π-π stacking between the pyridin...

The title compound, C(9)H(9)N(5), is slightly twisted from planarity, with a maximum deviation of 0.0285 (13) Å from the pyridine plane for the C atom bearing the amino group. The cyano groups are on different sides of the pyridine plane, with C- and N-atom deviations of 0.072 (3)/0.124 (4) and -0.228 (4)/-0.409 (5) Å from the pyridine plane. In the crystal, N-H⋯N and C-H⋯N hydrogen bonds conne...