7-Chloro-4-[(E)-2-(2-methoxybenzylidene)hydrazin-1-yl]quinoline monohydrate

In the title hydrate, C17H14ClN3O·H2O, the dihedral angle between the quinoline fused-ring system and the benzene ring is 13.4 (2)° and the conformation about the C=N bond is E. In the crystal, Nh—H⋯Ow and Ow—H⋯Nq (h = hydrozone, w = water and q = quinoline) hydrogen bonds generate a two-dimenstional network in the ac plane. A weak C—H⋯O interaction helps to consolidate the packing.

In the title hydrate, C 17 H 14 ClN 3 OÁH 2 O, the dihedral angle between the quinoline fused-ring system and the benzene ring is 13.4 (2) and the conformation about the C N bond is E. In the crystal, N h -HÁ Á ÁO w and O w -HÁ Á ÁN q (h = hydrozone, w = water and q = quinoline) hydrogen bonds generate a twodimenstional network in the ac plane. A weak C-HÁ Á ÁO interaction helps to consolidate the packing.
The use of the EPSRC X-ray crystallographic service at the University of Southampton, England, and the valuable assistance of the staff there is gratefully acknowledged. JLW acknowledges support from CAPES (Brazil).

Comment
Quinoline derivatives are known to display pharmacological potential (Warshakoon et al., 2006) and are being investigated for their anti-malarial activity (Andrade et al. 2007;de Souza et al., 2005). Structural studies on quinoline derivatives augment the biological investigations (Kaiser et al., 2009;de Lima Ferreira et al., 2010) and as a part of these studies, the crystal structure of the title hydrate, (I), was investigated.
The most significant twist in the quinoline molecule of (I), Fig. 1, occurs around the C10-C11 bond as seen in the N3-C10-C11-C16 torsion angle of 6.9 (9) °. This accounts for the dihedral angle of 13.4 (2) ° formed between the quinoline fused-ring system and the benzene ring. The conformation about the C10═N3 bond [1.282 (8) Å] is E. The crystal packing is stabilised by a variety of hydrogen bonding interactions, Table 1. The water molecule accepts a hydrogen bond from the hydrazone-N2 atom and bridges two symmetry related molecules by forming donor interactions with quinoline-N1 atoms; the water-O atom also participates in a C-H···O contact, Table 1

Refinement
The N-and C-bound H atoms were geometrically placed (N-H = 0.88 Å and C-H = 0.95-0.98 Å) and refined as riding with U iso (H) = 1.2-1.5U eq (C,N). The water-bound H atoms were located from a difference map and refined with U iso (H) = 1.5U eq (O).   Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.