The structure of 9-(3-bromo-6-chloro-2-hy-droxy-phen-yl)-10-(2-hy-droxy-ethyl)-3,6-diphenyl-3,4,5,6,7,9-hexa-hydro-2H-acridine-1,8-dione.

In the structure of the title compound C33H29BrClNO4, (I), the hexa-hydro-2H-acridine ring system has a hy-droxy-ethyl substituent on the N atom and a 3-bromo-6-chloro-2-hy-droxy-phenyl substituent on the central C atom at the 9-position. An unusual feature of the mol-ecule is that the substituents at the 3- and 5-positions of the outer cyclo-hexenone rings are phenyl rings rather than the more common dimethyl substituents. C atoms on both of the cyclo-hexenone rings are disordered over two sites. In the crystal structure, O-H⋯O, C-H⋯O and C-H⋯π(ring) hydrogen bonds combine with an Br-O and unusual C-Br⋯π(ring) halogen bonds to generate a three dimensional network with mol-ecules stacked along the a-axis direction.

Crystal structure of 1-(2,4-di-nitro-phen-yl)-3,5-diphenyl-1H-pyrazole.

In the title mol-ecule, C21H14N4O4, the phenyl rings make dihedral angles of 39.61 (8) and 9.4 (1)°, respectively, with the central pyrazole ring. The dihedral angle between the pyrazole and di-nitro-phenyl rings is 46.95 (5)°. In the crystal, mol-ecules pack in helical stacks parallel to the a axis aided by weak C-H⋯O inter-actions.

Crystal structure of 4-[(E)-(4-hy-droxy-benzyl-idene)amino]-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one.

The asymmetric unit of the title compound, C18H17N3O2, comprises three independent mol-ecules (1, 2 and 3). In mol-ecule 1, the dihedral angles between the pyrazolone ring and the pendant phenyl and hydroxybenzene rings are 54.43 (6) and 28.72 (6)°, respectively. The corresponding data for mol-ecule 2 are 86.84 (6) and 25.69 (5)°, respectively, and for mol-ecule 3 are 47.41 (7) and 17.09 (7)°, respectively. The three mol-ecules feature an intra-molecular C-H⋯O inter-action, which closes an S(6) ring in each case. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, which generate [100] chains incorporating all three asymmetric mol-ecules. Two weak C-H⋯O interactions connect three independent molecules to each other along the c-axis direction.

Crystal structure of 2-(2,3-di-methyl-anilino)-N'-[(1E)-2-hy-droxy-benzyl-idene]benzohydrazide.

The asymmetric unit of the title compound, C22H21N3O2, consists of two independent mol-ecules (A and B) having differing conformations. The differences mainly concern the dihedral angles which the hy-droxy-phenyl and di-methyl-phenyl rings subtend to the central phenyl-ene ring, these being 30.16 (6) and 58.60 (6)° in mol-ecule A and 13.42 (7) and 60.31 (7)° in B. With the exception of the dimethyphenyl substituent, the conformations of the rest of each mol-ecule are largely determined by intra-molecular O-H⋯N and N-H⋯O hydrogen bonds. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into chains extending parallel to the a axis in which the types of mol-ecules alternate in an …A…B…A…B… fashion.