In the title compound, C 13 H 10 N 2 O 3 , the dihedral angle between the planes of the two aryl rings is 7. 42 (10) . An intramolecular O-HÁ Á ÁN hydrogen bond generates an S(6) ring. The crystal structure features C-HÁ Á ÁO hydrogen bonds. Structure descriptionWe report here the synthesis and characterization of the title Schiff base derivative (Fig. 1)) prepared from the condensation reaction of an equimolar proportion of 5-nitrosalicylaldehyde and aniline in CCl 4 . The diversified nature of salicylaldehyde derivatives containing Schiff bases as an integral part of the structure exhibit a variety of important biological properties, including anti-bacterial, anti-cancer and anti-tumor activities (Ida Malarselvi et al., 2016).The benzene and phenyl rings are inclined at 7.42 (10) to one another. The molecule has an E conformation about the C N bond, and the C5-C7 N2-C8 torsion angle is À177. 03 (16) . The 4-nitro group is slightly tilted away from the benzene ring to which it is attached [O1-N1-C1-C2 = À5.8 (3) and O2-N1-C1-C6 = À2.7 (3) ]. The strong intramolecular O3-H3AÁ Á ÁN2 hydrogen bond (NÁ Á ÁH distance of 1.83 Å ) generates an S(6) ring. The strong band in the IR at 1632 cm À1 is assigned to the C7 N2 stretching frequency of the imine group of Schiff base with the C7 N2 bond distance of 1.276 (2) Å indicative of double-bond character. The crystal structure features C2-H2Á Á ÁO1 and C7-H7Á Á ÁO2 hydrogen bonds (Table 1, Fig. 2). Yan et al., (2014) have reported the crystal structure of 4-bromo-2-[(phenylimino)-methyl]phenol, in which the molecule is essentially planar (r.m.s. deviation = 0.026 Å ).

The title compound, C 13 H 10 FNO, is essentially planar (r.m.s. deviation = 0.022 Å ) and the dihedral angle between the planes of the two aryl rings is 0.69 (15) . An intramolecular O-HÁ Á ÁN hydrogen bond generates an S(6) ring. The crystal structure features C-HÁ Á ÁO hydrogen bonds. Structure descriptionWe report here, as part of our ongoing research (Ida Malarselvi et al., 2016), the synthesis and crystal structure ( Fig. 1), of the title fluorinated Schiff base compound, synthesized from the condensation reaction of equimolar amounts of 5-fluorosalicylaldehyde and aniline in DMSO. In this structure, the benzene and phenyl rings subtend a dihedral angle of 0.69 (15) . The molecule has an E conformation about the C N bond, and the C1-C7 N1-C8 torsion angle is 180.0 (2). There is a strong intramolecular O1-H1Á Á ÁN1 hydrogen bond [HÁ Á ÁN = 1.70 (5) Å ], which generates an S(6) ring. The crystal structure features C7-H7Á Á ÁO1 hydrogen bonds (see Table 1

The title compound, C 14 H 13 NO, is not planar with the dihedral angle between the planes of the two aryl rings being 6.22 (11) . The configuration about the imine bond is E. An intramolecular O-HÁ Á ÁN hydrogen bond generates an S(6) loop. In the crystal, molecules assemble into columns parallel to the a axis. The methyl group is disordered over two positions rotated from each other by 60 . Structure descriptionWe report here, as part of our on-going research (Ida Malarselvi et al., 2016;Swetha et al., 2017), the synthesis and the X-ray crystal structure of the title methylated Schiff base compound, Fig.1, synthesized from the condensation reaction of equimolar amounts of 5-methylsalicylaldehyde and aniline in a mixture of DMSO and CCl 4 . The benzene and phenyl rings deviate from co-planarity with the dihedral angle between the two rings being 6.22 (11) . The molecule has an E configuration about the C N bond; the C2-C7 N1-C8 torsion angle is À177. 73 (17) . There is an intramolecular O1-H1Á Á ÁN1 hydrogen bond with an HÁ Á ÁN distance of 1.73 (3) Å generating an S(6) loop, see Table 1 and Fig. 1. In the crystal, molecules assemble into columns parallel to the a axis, Fig. 2. Swetha et al. (2017) have reported the crystal structure of (E)-4-fluoro-2-[(phenylimino)methyl]phenol, in which the molecule is essentially planar (r.m.s. deviation = 0.022 Å ) and the dihedral angle between the planes of the two aryl rings is 0.69 (15) .

The title compound, C13H10INO, is not planar as the dihedral angle between the planes of the two aryl rings is 44.5 (9)°. The configuration about the central C=N bond is E, and there is an intramolecular O—H...N hydrogen bond which generates an S(6) ring. The molecular packing is stabilized by weak C—H...π interactions. The structure was refined as a two-component inversion twin.

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