Dibromido[N-propyl-N′-(2-pyridylmethylidene)ethane-1,2-diamine]zinc(II)

The title complex, [ZnBr2(C11H17N3)], is a mononuclear zinc(II) compound derived from the Schiff base N-propyl-N′-(1-pyridin-2-ylmethylidene)ethane-1,2-diamine. The ZnII atom is five-coordinate, binding to the imine N, pyridine N, and amine N atoms of the Schiff base ligand and to two bromide anions in a distorted trigonal-bipyramidal coordination geometry. Adjacent molecules are linked through intermolecular N—H⋯Br hydrogen bonds, forming dimers.

The title complex, [ZnBr 2 (C 11 H 17 N 3 )], is a mononuclear zinc(II) compound derived from the Schiff base N-propyl-N 0 -(1-pyridin-2-ylmethylidene)ethane-1,2-diamine. The Zn II atom is five-coordinate, binding to the imine N, pyridine N, and amine N atoms of the Schiff base ligand and to two bromide anions in a distorted trigonal-bipyramidal coordination geometry. Adjacent molecules are linked through intermolecular N-HÁ Á ÁBr hydrogen bonds, forming dimers.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ2523). Sheldrick, G. M. (2008 X.-W. Zhu and X.-Z. Yang
The Zn II atom in (I) is five-coordinated by one imine N, one pyridine N, and one amine N atoms of the Schiff base ligand, and by two Branions, in a distorted trigonal-bipyramidal coordination geometry. The coordinate bond lengths (Table 1)  In the crystal structure, adjacent molecules are linked through intermolecular N-H···Br hydrogen bonds (Table 2), forming dimers ( Fig. 2).

Experimental
The Schiff base compound was prepared by the condensation of equimolar amounts of pyridine-2-carbaldehyde with N-propylethane-1,2-diamine in a methanol solution. The complex was prepared by the following method. To an anhydrous methanol solution (5 ml) of ZnBr 2 (22.5 mg, 0.1 mmol) was added a methanol solution (10 ml) of the Schiff base compound (19.1 mg, 0.1 mmol) with stirring. The mixture was stirred for 30 min at room temperature and filtered. Upon keeping the filtrate in air for a few days, colorless block-shaped crystals formed at the bottom of the vessel on slow evaporation of the solvent.

Refinement
H3A attached to N3 was located from a difference Fourier map and refined isotropically, with the N-H distance restrained to 0.90 (1) Å, and with U iso (H) fixed at 0.08 Å 2 . Other H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C-H distances in the range 0.93-0.97Å and with U iso (H) = 1.2U eq (C) and 1.5U eq (methyl C).
supplementary materials sup-2 Figures   Fig. 1. The molecular structure of (I) with ellipsoids drawn at the 30% probability level. Fig. 2. The crystal packing of (I), viewed along the a axis.

Dibromido[N-propyl-N'-(2-pyridylmethylidene)ethane-1,2-diamine]zinc(II)
Crystal data [ZnBr 2 (C 11  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 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.