4-[(E)-({4-[Bis(2-hydroxyethyl)amino]phenyl}imino)methyl]phenol

In the title compound, C17H20N2O3, the amino N atom is in a planar environment (sum of angles = 360.0°). All hydroxy H atoms are involved in hydrogen bonding. In the crystal structure, two O—H⋯O and an O—H⋯Nimino hydrogen bond result in the formation of a three-dimensional network. The latter hydrogen bonding causes distortion of the planarity of the 4-HO–C6H4–CH=N–C6H4– fragment by rotation around the =N—CPh bond. The crystal studied was a non-merohedral twin [refined BASF parameter for the major component = 0.5293 (7)].

In the title compound, C 17 H 20 N 2 O 3 , the amino N atom is in a planar environment (sum of angles = 360.0 ). All hydroxy H atoms are involved in hydrogen bonding. In the crystal structure, two O-HÁ Á ÁO and an O-HÁ Á ÁN imino hydrogen bond result in the formation of a three-dimensional network. The latter hydrogen bonding causes distortion of the planarity of the 4-HO-C 6 H 4 -CH N-C 6 H 4 -fragment by rotation around the N-C Ph bond. The crystal studied was a nonmerohedral twin [refined BASF parameter for the major component = 0.5293 (7)].

D-HÁ
Experimental . Single crystal of (I) suitable for X-ray diffraction analysis was picked up directly from the obtained materials.

Refinement
All non-H atoms were refined anisotropically. H atoms except of H7 and OH group ones were treated as riding atoms with distances C-H = 0.97 (CH 2 ), 0.93 Å (C Ar H), and U iso (H) = 1.2U eq (C). Atoms H7 and OH group H atoms were found from difference Fourier syntheses and refined isotropically. Fig. 1. Asymmetric unit of the compound (I) with labelling and thermal ellipsoids at the 50% probability level.

Special details
Experimental. Sample of (I) was a two-component non-merohedral twin with approximately equal component contribution. Thus, the structure of (I) was solved and pre-refined for one of the components (HKLF 4 format) and finally refined for the full set of reflexions (HKLF 5 file format). The refined BASF parameter for the prevailing component equals 0.5293 (7).
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
supplementary materials sup-4 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.