Crystal structure of {2-[({2-[(2-aminoethyl)amino]ethyl}imino)methyl]phenolato}aquacopper(II) bromide

In the mononuclear copper(II) title complex, [Cu(C11H16N3O)(H2O)]Br, the CuII atom is coordinated by one O and three N atoms of the Schiff base ligand that forms together with one water molecule a slightly distorted [CuN3O2] square-pyramidal polyhedron. The deviation of the CuII atom from the mean equatorial plane is 0.182 (2) Å. The equatorial plane is nearly coplanar to the aromatic ring of the ligand [angle between planes = 10.4 (1)°], and the water molecule is situated in the apical site. All coordinating atoms (except the imine nitrogen) and the bromide ion contribute to the formation of the N—H⋯Br, O—H⋯Br and O—H⋯O hydrogen bonds, which link molecules into chains along [01-1].

The title compound, [Cu(C 11 H 18 N 3 O 2 )(H 2 O)]Br, was obtained unintentionally as the product of an attempted synthesis of a Cu/ Mn heterometallic complex using zerovalent copper and manganese powders, ammonium bromide, salicylic aldehyde and diethylenetriamine in dimethylformamide on air.
As shown in Fig. 1, the Cu II atom has a slightly distorted square-pyramidal geometry formed by one oxygen and three nitrogen atoms of the Schiff base ligand as well one oxygen atom of the coordinated water molecule. The deviation of the copper atom from the mean equatorial plane is 0.182 (2) (Zhu et al.,2002(Zhu et al., , 2004He et al., 2003). The equatorial plane is nearly coplanar to the aromatic ring of the ligand [angle between planes is 10.4 (1)°].
In the crystal, OH···O hydrogen bonds form molecular dimers. OH···Br and NH···Br hydrogen bonds link the dimers into chains along the [011] crystallographic direction (See Table containing Hydrogen-bond geometry and Fig.2).

S2. Experimental
The title compound was synthesized by addition of manganese powder 0.055 g (1 mmol), copper powder 0.06 g (1 mmol) and NH 4 Br 0.392 g (4 mmol) to the previously prepared Schiff base ligand solution [mixture of salicylic aldehyde 0.21 ml (2 mmol) and diethylenetriamine 0.108 ml (1 mmol) in dimethylformamide (10 ml) which was stirred about 15 min at 323-333 K until the mixture turned yellow]. The total reaction mixture was stirred magnetically for 4 h until the complete dissolution of manganese and copper powders was observed. Dark green crystals that precipitated after 1 day were collected by filtration and dried in air.

S3. Refinement
Structure was solved by direct method and refined against F 2 with anisotropic refinement for all non-hydrogen atoms. All Crystal packing of the title compound with hydrogen bonds shown as dashed lines. 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 > σ(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.