The asymmetric unit of the title compound, C(9)H(11)NO·C(6)H(5)N(3)O(4), contains two independent mol-ecules each of 4-(dimethyl-amino)-benzaldehyde and 2,4-dinitro-aniline. In the crystal, the components are linked by inter-molecular N-H⋯O hydrogen bonds to form one-dimensional chains along [10[Formula: see text]]. Intra-molecular N-H⋯O hydrogen bonds are also present.

The reactions of isatins, 3-amino-1-pheyl-1H-pyrazol-5(4H)-one, and monocyclic ketones, have been developed for preparation spiro[indoline-3,4'-pyrazolo[3,4-b]quinoline]-2,3'(6'H)-dione, spiro[cyclohepta[b]pyrazolo[4,3-e]pyridine-4,3'-indoline]-2′,3-dione, spiro[cycloocta[b]pyrazolo[4,3-e]pyridine-4,3'-indoline]-2′,3(6H)-dione, spiro[cyclo dodeca[b]pyrazolo[4,3-e]pyridine-4,3'-indoline]-2′,3(6H...

In the title compound, [Ru(C(13)H(7)Cl(2)N(5))(C(15)H(11)N(3))](PF(6))(2)·2CH(3)CN, the Ru(II) atom is coordinated in a distorted octa-hedral geometry by a tridentate 2,2':6',2''-terpyridine ligand and a tridentate 2,6-bis-(5-chloro-pyrimidin-2-yl)pyridine ligand. Least-squares mean-plane distortions of only 1.72 (2) and 2.91 (2)° of the pyrimidyl rings with respect to the central pyridine are ...

In the title compound, C7H5BrN2, fused six-membered pyridine and five-membered pyrrole rings form the essentially planar aza-indole skeleton (r.m.s. deviation = 0.017 Å). In the crystal, pairs of N-H⋯N hydrogen bonds connect the mol-ecules into inversion dimers.

In the title compound, C(11)H(7)F(2)N, the fluoro-benzene and the 2-fluoro-pyridine rings are oriented at a dihedral angle of 37.93 (5)°. In the crystal, only van der Waals inter-actions occur.

The asymmetric unit of the title compound, C(7)H(6)O(4)·C(5)H(5)N, consists of one 3,4-dihy-droxy-benzoic acid and one pyridine mol-ecule, both located on general positions. The 3,4-dihy-droxy-benzoic acid mol-ecules are arranged in layers and are connected by inter-molecular O-H⋯O hydrogen bonding, forming channels along the a axis in which the pyridine mol-ecules are located. The pyridine and...