(Z)-3-({[3-Meth-oxy-5-(tri-fluoro-meth-yl)phen-yl]imino}meth-yl)benzene-1,2-diol.

The title compound, C15H12F3NO3, crystallizes with one mol-ecule in the asymmetric unit. The mean planes of the two phenyl rings of the Schiff base moiety, bearing the OH groups and the imine group, respectively, are inclined to each other by 4.91 (1)°. In the crystal, mol-ecules are linked via pairs of bifurcated O-H⋯O hydrogen bonds between the phenol OH groups, forming inversion dimers with an R 1 2(5) ring motif. The structure exhibits also intra-molecular O-H⋯N and C-H⋯F hydrogen-bonding inter-actions. Hirshfeld surfaces analysis and two-dimensional fingerprint plots were applied to qu-antify the inter-molecular inter-actions. The three F atoms of the tri-fluoro-methyl group are disordered over two sets of sites, with occupancy factors of 0.578 (8) and 0.422 (8). The crystal studied was refined as an inversion twin.

Crystal structure and computational studies of (3Z)-4-benzoyl-3-[(2,4-di-nitro-phen-yl)hydrazinyl-idene]-5-phenyl-furan-2(3H)-one.

In the mol-ecular structure of the title compound, C23H14N4O7, the furan, di-nitro-phenyl and phenyl rings are almost in the same plane (r.m.s. deviation = 0.127 Å), with the benzoyl ring inclined by a dihedral angle of 56.4 (1)° to the three-ring system. A bifurcated intra-molecular N-H⋯(O,O) hydrogen bond is present. In the crystal, adjacent mol-ecules are linked by C-H⋯O hydrogen bonds into chains parallel to [001]. A π-π stacking inter-action between the benzoyl and di-nitro-phenyl moieties contributes to the crystal packing. Theoretical calculations using DFT(B3YLP) methods were used to confirm the mol-ecular structure.

Crystal structure and computational study of 2,4-di-chloro-N-[(E)-(5-nitro-thio-phen-2-yl)methyl-idene]aniline.

The title compound, C11H6Cl2N2O2S, is a Schiff base that incorporates an N-bound 2,4-di-chloro-phenyl and a C-bound 5-nitro-thio-phene ring. The mol-ecule is approximately planar, the maximum deviation from the mean plane being 0.233 (4) Šfor the C=N N atom. The dihedral angle between the benzene and thio-phene rings is 9.7 (2)°. The C=N double bond has an E configuration. The crystal structure features C-H⋯O hydrogen bonds,forming sheets parallel to (10-1), and π-π stacking inter-actions between symmetry-related thio-phene and benzene rings, in which the distance between adjacent ring centroids is 3.707 (4) Å, forming a three-dimensional supramolecular structure. Geometric parameters from quantum-chemical calculations are in good agreement with experimental X-ray diffraction results.