4-[(E)-2-(2-Chlorobenzylidene)hydrazin-1-yl]quinolin-1-ium chloride dihydrate

In the title hydrated salt, C16H13ClN3 +·Cl−·2H2O, a small twist is evident in the cation so that the chlorobenzene ring is not coplanar with the central hydrazinyl group [the N—C—C—C torsion angle = −4.8 (12)°]. The conformation about the imine N=C bond [1.284 (10) Å] is E. The components of the structure are connected into a three-dimensional architecture via O—H⋯O, O—H⋯Cl and N—H⋯Cl hydrogen bonds. One water H atom is disposed over two sites of equal occupancy.

In the title hydrated salt, C 16 H 13 ClN 3 + ÁCl À Á2H 2 O, a small twist is evident in the cation so that the chlorobenzene ring is not coplanar with the central hydrazinyl group [the N-C-C-C torsion angle = À4. 8 (12) ]. The conformation about the imine N C bond [1.284 (10) Å ] is E. The components of the structure are connected into a three-dimensional architecture via O-HÁ Á ÁO, O-HÁ Á ÁCl and N-HÁ Á ÁCl hydrogen bonds. One water H atom is disposed over two sites of equal occupancy.
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). Support from the Ministry of Higher Education, Malaysia, High-Impact Research scheme (UM.C/HIR/MOHE/SC/12) is gratefully acknowledged.  et al., 2011). Complementing synthetic studies are crystallographic investigations of these hydrazones . We have recently turned our attention to arylaldehyde quinoline-4-hydrazone derivatives  and now wish to report the crystal structure of the title hydrated salt, (I).
The asymmetric unit of (I), Fig two sites of equal occupancy with each involved in a significant hydrogen bonding interaction. While the structure has been determined unambiguously, the authors acknowledge that the structure determined is not optimal as seen, for example, in the poor precision in the C-C bonds.

Figure 1
The molecular structure showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.
Only one position of the disordered H atoms of the O2w water molecule is shown.    where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.46 e Å −3 Δρ min = −0.55 e Å −3 Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. 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 R-factors(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.