{4-Bromo-2-[3-(diethylammonio)propyliminomethyl]phenolato}diiodidozinc(II) methanol solvate

In the title complex, [ZnI2(C14H21BrN2O)]·CH3OH, the asymmetric unit consists of a mononuclear zinc(II) complex molecule and a methanol solvent molecule. The compound was derived from the zwitterionic form of the Schiff base 4-bromo-2-[3-(diethylamino)propyliminomethyl]phenol. The ZnII atom is four-coordinated by the imine N and phenolate O atoms of the Schiff base ligand and by two iodide ions in a distorted tetrahedral coordination. In the crystal structure, the methanol molecules are linked to the Schiff base molecules through N—H⋯O and O—H⋯O hydrogen bonds. One I atom is disordered over two positions in a 0.702 (19):0.298 (19) ratio.

The complex consists of a mononuclear zinc(II) complex molecule and a methanol molecule. The Zn II atom is four-coordinated by the imine N and phenolate O atoms of the zwitterionic form of the Schiff base ligand, and by two Iions, in a distorted tetrahedral coordination. The coordinate bond lengths (Table 1) are typical and comparable to the corresponding values observed in the Schiff base zinc complexes we reported previously and other similar Schiff base zinc complexes Wei et al., 2007;Qiu, 2006a,b). I2 atom is disordered over two positions [0.702(19/0.298 (19)].
In the crystal structure, the methanol molecules are linked to the Schiff base molecules through O-H···O and N-H···O hydrogen bonds generating a graph-set motif C 2 2 (10) chain along [100] direction (

Experimental
The Schiff base compound was prepared by the condensation of equimolar amounts of 5-bromosalicylaldehyde with N,Ndiethylpropane-1,3-diamine in a methanol solution. The complex was prepared by the following method. To an anhydrous methanol solution (5 ml) of ZnI 2 (31.9 mg, 0.1 mmol) was added a methanol solution (10 ml) of the Schiff base compound (31.3 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 were formed.

Refinement
H2A was located from a difference Fourier map and refined isotropically, with N-H distance restrained to 0.90 (1) Å.
Other H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C-H distances in the range 0.93-0.97 Å, O-H distance of 0.82 Å, and with U iso (H) = 1.2U eq (C) and 1.5U eq (methyl C and O).
The I2 atom is disordered over two distinct sites with occupancies of 0.702 (2) and 0.298 (2), respectively. Fig. 1. The molecular structure of the title complex, with ellipsoids drawn at the 30% probability level.

Special details
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.
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 > 2sigma(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.