Dichlorido{2-[3-(dimethyl­ammonio)­propyl­imino­meth­yl]phenolato}zinc(II) hemihydrate

Xue-Wen Zhu

doi:10.1107/S1600536808033977

. 2008 Oct 25;64(Pt 11):m1456–m1457. doi: 10.1107/S1600536808033977

Dichlorido{2-[3-(dimethylammonio)propyliminomethyl]phenolato}zinc(II) hemihydrate

Xue-Wen Zhu ^a,^*

PMCID: PMC2959570 PMID: 21580895

Abstract

The title complex, [ZnCl₂(C₁₂H₁₈N₂O)]·0.5H₂O, is a mononuclear zinc(II) compound derived from the zwitterionic form of the Schiff base 2-[3-(dimethylamino)propyliminomethyl]phenol. The Zn^II atom is four-coordinated by the imine N and the phenolate O atoms of the Schiff base ligand, and by two chloride ions, in a distorted tetrahedral coordination geometry. The dimethylammonio group is disordered over two positions with site occupancies of 0.51 (3) and 0.49 (3). In the asymmetric unit, there is also a disordered water molecule with a partial occupancy of 0.5. In the crystal structure, the water molecules are linked to the Schiff base complex molecules through intermolecular N—H⋯O hydrogen bonds. Molecules are further linked through additional intermolecular N—H⋯O hydrogen bonds, forming chains running along the b axis.

Related literature

For a general background on the chemistry of Schiff base complexes, see: Ali et al. (2008 ▶); Biswas et al. (2008 ▶); Chen et al. (2008 ▶); Darensbourg & Frantz (2007 ▶); Habibi et al. (2007 ▶); Kawamoto et al. (2008 ▶); Lipscomb & Sträter (1996 ▶); Tomat et al. (2007 ▶); Wu et al. (2008 ▶); Yuan et al. (2007 ▶). For related structures, see: Zhu & Yang (2008a ▶,b ▶,c ▶,d ▶); Qiu (2006a ▶,b ▶); Wei et al. (2007 ▶); Zhu et al. (2007 ▶).

Experimental

Crystal data

[ZnCl₂(C₁₂H₁₈N₂O)]·0.5H₂O
M _r = 351.58
Orthorhombic,
a = 13.335 (2) Å
b = 16.384 (2) Å
c = 7.212 (1) Å
V = 1575.7 (4) Å³
Z = 4
Mo Kα radiation
μ = 1.89 mm⁻¹
T = 298 (2) K
0.23 × 0.23 × 0.22 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.650, T _max = 0.661
12635 measured reflections
3426 independent reflections
2915 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.103
S = 1.08
3426 reflections
206 parameters
4 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.42 e Å⁻³
Δρ_min = −0.40 e Å⁻³
Absolute structure: Flack (1983 ▶), 1569 Friedel pairs
Flack parameter: 0.03 (2)

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808033977/rz2256sup1.cif

e-64-m1456-sup1.cif^{(18.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808033977/rz2256Isup2.hkl

e-64-m1456-Isup2.hkl^{(168KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Zn1—O1	1.954 (3)
Zn1—N1	2.003 (4)
Zn1—Cl1	2.2182 (13)
Zn1—Cl2	2.2692 (18)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2′—H2′A⋯O1ⁱ	0.91	1.88	2.762 (14)	164
N2—H2C⋯O1ⁱ	0.91	1.87	2.773 (12)	170

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

Schiff bases have widely been used as versatile ligands in coordination chemistry (Biswas et al., 2008; Wu et al., 2008; Kawamoto et al., 2008; Ali et al., 2008; Habibi et al., 2007), and their metal complexes are of great interest in many fields (Chen et al., 2008; Yuan et al., 2007; Tomat et al., 2007; Darensbourg & Frantz, 2007). Zinc(II) is an important element in biological systems and functions as an active site of hydrolytic enzymes, such as carboxypeptidase and carbonic anhydrase where it is in a hard-donor coordination environment of nitrogen and oxygen ligands (Lipscomb & Sträter, 1996). Recently, we have reported some Schiff base complexes (Zhu & Yang, 2008a,b,c,d). In this paper, the synthesis and structural characterization of a new zinc(II) complex (Fig. 1) of the Schiff base ligand 2-[(3-dimethylaminopropylimino)methyl]phenol is reported.

The zinc(II) atom in the title compound is four-coordinated by the imine N and phenolate O atoms of the zwitterionic form of the Schiff base ligand, and by two Cl^- ions in a tetrahedral coordination geometry. The coordinate bond lengths (Table 1) are typical and comparable to the corresponding values observed in other similar zinc(II) Schiff base complexes (Zhu et al., 2007; Wei et al., 2007; Qiu, 2006a,b).

In the crystal structure, the water molecules are linked to the Schiff base complex molecules through intermolecular N–H···O hydrogen bonds (Table 2). The molecules are further linked through intermolecular N–H···O hydrogen bonds (Table 2), forming chains running along the b axis (Fig. 2).

Experimental

The Schiff base compound was prepared by the condensation of equimolar amounts of salicylaldehyde with N,N-dimethylpropane-1,3-diamine in a methanol solution. The complex was prepared by the following method: to an anhydrous methanol solution (5 ml) of ZnCl₂ (13.7 mg, 0.1 mmol) was added a methanol solution (10 ml) of the Schiff base compound (20.6 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, colourless block-shaped crystals were formed at the bottom of the vessel on slow evaporation of the solvent.