[N-(3-Meth­oxy-2-oxidobenzyl­idene-κO 2)threoninato-κ2 O 1,N](1,10-phenanthroline-κ2 N,N′)copper(II) hemihydrate

Buqin Jing; Lianzhi Li; Jianfang Dong; Jinghong Li

doi:10.1107/S1600536811012049

. 2011 Apr 7;67(Pt 5):m536. doi: 10.1107/S1600536811012049

[N-(3-Methoxy-2-oxidobenzylidene-κO ²)threoninato-κ² O ¹,N](1,10-phenanthroline-κ² N,N′)copper(II) hemihydrate

Buqin Jing ^a,^b, Lianzhi Li ^b,^*, Jianfang Dong ^c, Jinghong Li ^b

PMCID: PMC3089306 PMID: 21754276

Abstract

In the title complex, [Cu(C₁₂H₁₃NO₅)(C₁₂H₈N₂)]·0.5H₂O, the Cu^II ion is five-coordinated by one N atom and two O atoms from a tridentate Schiff base ligand, derived from the condensation of l-threonine and o-vanillin, and two N atoms from a 1,10-phenanthroline ligand in a distorted square-pyramidal geometry. In the crystal, intermolecular O—H⋯O hydrogen bonds form a one-dimensional left-handed helical structureextending parallel to [001]. The water molecule of crystallization shows half-occupancy.

Related literature

For general background to Schiff bases and their metal complexes, see: Chohan et al. (1998 ▶); Nath et al. (2001 ▶); Yamada (1966 ▶). For structures of related complexes with five-coordinate copper(II) derived from amino acid Schiff base ligands, see: Huang et al. (2010 ▶); Qiu et al. (2008 ▶).

Experimental

Crystal data

[Cu(C₁₂H₁₃NO₅)(C₁₂H₈N₂)]·0.5H₂O
M _r = 503.99
Tetragonal,
a = 22.527 (6) Å
c = 10.290 (4) Å
V = 5222 (3) Å³
Z = 8
Mo Kα radiation
μ = 0.87 mm⁻¹
T = 293 K
0.50 × 0.15 × 0.11 mm

Data collection

Bruker SMART 1000 CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.669, T _max = 0.910
13788 measured reflections
4560 independent reflections
2419 reflections with I > 2σ(I)
R _int = 0.084

Refinement

R[F ² > 2σ(F ²)] = 0.076
wR(F ²) = 0.267
S = 0.90
4560 reflections
307 parameters
511 restraints
H-atom parameters constrained
Δρ_max = 0.83 e Å⁻³
Δρ_min = −0.40 e Å⁻³
Absolute structure: Flack (1983 ▶), 2126 Friedel pairs
Flack parameter: −0.13 (5)

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); 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/S1600536811012049/hy2419sup1.cif

e-67-0m536-sup1.cif^{(19.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811012049/hy2419Isup2.hkl

e-67-0m536-Isup2.hkl^{(223.5KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Cu1—N1	1.940 (8)
Cu1—N2	2.263 (9)
Cu1—N3	2.004 (8)
Cu1—O1	1.966 (6)
Cu1—O4	1.924 (7)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O2ⁱ	0.82	2.10	2.767 (11)	138

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the Natural Science Foundation of Shandong Province (No. Y2004B02) for a research grant.

supplementary crystallographic information

Comment

Schiff bases still play an important role as ligands in metal coordination chemistry even after almost a century since their discovery (Yamada et al., 1966). It has been reported that amino acid Schiff bases and their first row transition metal complexes exhibit fungicidal, bactericidal, antiviral and antitubercular activities (Chohan et al., 1998; Nath et al., 2001). Herein, we report the synthesis and crystal structure of a new copper(II) complex with a tridentate Schiff base ligand, derived from the condensation of L-threonine and o-vanillin, and a 1,10-phenanthroline coligand.

The title complex has a mononuclear structure with an amino acid Schiff base ligand and a 1,10-phenanthroline ligand. As shown in Fig. 1, the Cu^II ion is five-coordinated by one N atom and two O atoms from the Schiff base ligand and by two N atoms from the 1,10-phenanthroline ligand, forming a seriously distorted square-pyramidal geometry. O1, O4, N1 and N3 atoms are located in the basal plane and N2 atom in the apical position. The Cu^II ion lies 0.1651 (4) Å above the basal plane towards N2. The Cu1—N2 bond is significantly longer [2.263 (9) Å] (Table 1) as seen previously [2.298 (4) Å] (Huang et al., 2010) and [2.231 (3) Å] (Qiu et al., 2008). In the crystal, intermolecular O3—H3···O2ⁱ (symmetry code: 3/2-y, -1/2+x, -1/2+z) hydrogen bonds (Table 2) form a one-dimensional left-handed helical structure (Fig. 2).

Experimental

L-Threonine (1 mmol, 119 mg) and potassium hydroxide (1 mmol, 56 mg) were dissolved in hot methanol (10 ml) and added successively to a methanol solution of o-vanillin (1 mmol, 152 mg). The mixture was then stirred at 323 K for 2 h. Subsequently, an aqueous solution (2 ml) of cupric acetate hydrate (1 mmol, 200 mg) was added dropwise and stirred for 2 h. A methanol solution (5 ml) of phenanthroline (1 mmol, 198 mg) was added dropwise and stirred for 4 h. The solution was held at room temperature for two weeks, whereupon green block-shaped crystals suitable for X-ray diffraction were obtained.